According to Catholicism, when is vandalism not sinful?

1. A good answer would be an explanation of what makes destroying of the property a sin...

The seventh commendement (You shall not steal) implies the right for every body to private ownship. The Compendium of the Social Doctrine of the Church says :

  Private property and other forms of private ownership of goods assure a person a highly necessary sphere for the exercise of his personal and family autonomy and ought to be considered as an extension of human freedom ... stimulating exercise of responsibility, it constitutes one of the conditions for civil liberty

2. ... and how this logic can be applied to the given examples

A poster may no longer be considered as a personal belonging. Tearing it down could be see as an expression of your opinion, your freedom. The Compendium of the Social Doctrine of the Church gives several definitions of freedom. One of them is:

  freedom must also be expressed as the capacity to refuse what is morally negative, in whatever guise it may be presented, ...

But just before this definition, it states about the exercice of freedom.

  This must take place within a “strong juridical framework”, within the limits imposed by the common good and public order, and, in every case, in a manner characterized by responsibility.

Please note that displaying a poster that calls for some atrocities or displays pornography may be punished by law.

The scene of Jesus with the vendors in the Temple (cf. John 2:14-16) shows that there is not a general rule about the immorality of destroying others's belongings when their use/presence offends. However, whoever destroys the property of others while civil law doesn't condone it may be punished if discovered.

3. What is the source of "good" - is something good because God says so? Or maybe God says what is good ?

This is a huge question that cannot be answered within a few lines. You can have further information by looking for ressources related to the sources of morality.

4. I'm also interested in the relation to the law ...

Law may vary from one contry to another.

5. From my understanding, in most cases breaking a law is a sin (as all authority comes from the God)

Check out this quote of the Catechism of the Catholic Church:

  The citizen is obliged in conscience not to follow the directives of civil authorities when they are contrary to the demands of the moral order, to the fundamental rights of persons or the teachings of the Gospel. Refusing obedience to civil authorities, when their demands are contrary to those of an upright conscience, finds its justification in the distinction between serving God and serving the political community. "Render therefore to Caesar the things that are Caesar's, and to God the things that are God's." (Mt 22:21) "We must obey God rather than men" (Acts 5:29)

  .When citizens are under the oppression of a public authority which oversteps its competence, they should still not refuse to give or to do what is objectively demanded of them by the common good; but it is legitimate for them to defend their own rights and those of their fellow citizens against the abuse of this authority within the limits of the natural law and the Law of the Gospel.


From Clergy | oca.org (Orthodox Church in America), the rector is appointed by the Diocesan Bishop and cannot leave his parish without the permission of the Bishop.

Below is the entire section:

  At the head of the parish is its Rector. According to the teachings of
  the Church, he is the spiritual father and teacher of his flock and
  the celebrant of the liturgical worship established by the Church. He
  teaches and edifies the People of God entrusted to his spiritual care
  "with no partiality" (James 2:1) and sees to it that all activities
  within the parish serve the religious goals of the Church.

  The rector is appointed by the Diocesan Bishop and cannot leave his
  parish without the permission of the Bishop. No activities in the
  parish can be initiated without his knowledge, approval, and blessing;
  neither should he do anything pertaining to the parish without the
  knowledge of his parishioners and parish organs elected by them, so
  that always and everywhere there may be unity, mutual trust,
  cooperation, and love. In conformity with his teaching office, the
  Rector shall have final authority over the church school. To be free
  from material preoccupations and wholly committed to his sacred
  ministry, the priest must be compensated by the parish, the amount of
  his compensation being clearly agreed upon at the time of his
  appointment.

See also: Article X: The Parish | The Statute of the Orthodox Church in America.

Answering Say for instance, his wife had strong family ties in a certain state. Could he request assignment in a certain state? How likely is that request to be granted?

I would say first step is for the rector to speak with his Bishop.


How was the gift of the word of knowledge defined by the pioneers of the pentecostal healing revival

W. V. Grant wrote in THE VOICE OF HEALING October 1953 Page 24 about the word of knowledge.

  WHAT IT IS

  The Spiritual gift of the word of knowledge is certain
  facts in the mind of God, which He sees fit to reveal to a servant
  supernaturally by His Spirit. It is only a “word,” or a portion of
  God's great storehouse of knowledge. God speaks in divers manners,
  such as dreams, visions, revelation, or in audible voice. It is always
  conveyed supernaturally as any other gift. This gift can tell the
  whereabouts, conditions, nature, or thoughts of a person, animal,
  place, or thing even when it is impossible to learn it in the natural.

  It is different from the Spiritual gift of faith in that it lets you
  know things even when you did not pray for them. The Spiritual gift of
  faith deals with things “not yet come to pass,” else it would not be
  faith. It is not a vocal gift, as it makes you to know and not to
  speak. It is not discerning of spirits, as it has nothing to do with a
  supernatural spirit. It helps one, to look into the heart, mind, or
  nature of a man and to know his secrets and intentions. It has helped
  people find lost articles, but its main purpose is to find lost souls.

  BIBLE EXAMPLES

  While Peter was lying flat on his back on the house
  top, the Spirit of God told him three men were seeking him (Acts
  10:19). Had Peter gone to school one hundred years he could not have
  gained such knowledge, The all-knowing God gave part of His knowledge
  to Peter by the Spirit.

  The Spirit of God told Samuel that Saul's
  asses had already been found, and let him know all that was in Saul's
  heart (1 Sam. 9.19-20). A voice from God told Elijah that God had
  seven thousand who had not bowed their knees to Baal (1 Kings 19:18).
  A spiritual revelation!

And before that he wrote, in direct contrast to pentecostal pioneer Donald Gee:

  This gift has no mixture with the natural.

Now I only need to know if this view was shared by the other leaders during the same era.


Why do the majority of Protestants celebrate Easter on the same day as the Catholic Church?

Protestants have not used the same date for Easter as Catholics for every year since 1518. They did until 1582, but in 1583 the Pope introduced the Gregorian Calendar. From then on Protestants generally calculated Easter in the traditional way, using the Julian Calendar, still used in most Orthodox churches.

The original principle related Easter to the Full Moon after the Equinox and ruled the equinox was March 21. By the sixteenth century the rule was out of kilter with the principle. From 1583 to 1752 Easter was usually celebrated by Protestants, in the British Empire, later than Catholics. In some parts of Germany a different method was used from 1700 and it survived in  Sweden into the 19th century.  It was astronomically based.

Sir Isaac Newton tried to introduce an astronomically fairly accurate method in England,  but eventually gave up saying the English would rather disagree with the sun and moon than agree with the pope. In 1752 the British Parliament decided to align the calendar generally with the Gregorian Calendar, though calling it the Georgian Calendar, and tables for Easter were produced on the Roman basis, though differently presented. This applied throughout the British Empire although it was binding only on the Church of England,  Church of Scotland and Church of Ireland, as regards religious observance.


Do we have or know of additional writings from the four Gospel Evangelists?

There is Secret Mark. Its authenticity is debatable, but it purports to be the  advanced version of the Gospel of Mark.


What is the biblical basis for a continued illness indicating unforgiven sin?

In Mark 2:1-12, Jesus attributes the man's sickness to his sin -- "Son, thy sins be forgiven thee" -- which means it arose as the result of some behaviour of his that was counter to the commandments of God. In John 9:1-11, however, Jesus says that neither the blind man nor his parents had sinned, so his disability was attributable to the accumulated consequences of mankind's longterm ignorance/defiance of the commandments of God.

Whether or not illness/disability is attributable to one's own sin or to the accumulated sin of mankind, living life within the safety net of the commandments of God WILL bring a better outcome for one's life into the future.

As Nebuchadnezzar was about to throw Daniel's friends into the fiery furnace for failing to bow to his image, he said, "And who is the god who will deliver you from my hands?". Their reply to him was:

  O Nebuchadnezzar, we have no need to answer you in this matter. If that is the case, our God whom we serve is able to deliver us from the burning fiery furnace, and He will deliver us from your hand, O king. But if not, let it be known to you, O king, that we do not serve your gods, nor will we worship the gold image which you have set up.
  -- Daniel 3:16-18 (NKJV)

They had no expectation of salvation from their fate. Yes, they believed God could rescue them, but even if He chose not to, they were still not going to be moved from their course.

Conclusion

One's attitude towards delivery from the fiery furnace of illness and disability must be the same as Daniel's three friends -- "My God whom I serve is able to deliver me from illness and disability, but if not, let it be known that I will live according to His law, and I will not be moved to serve any other!"

I included the following graphic in another answer, but it bears including here as well.

Each person has only two courses: they will either set their heart to pursue God's pleasure or to pursue their own. The path to blessing, however, is unmistakable and immutable.

He who has ears to hear, let him hear.


In Matthew 26:63-64, does the high priest think that the Messiah is Son of God?

Several Second Temple documents — and not just the Christian tradition — reflect the hope that God will re-establish the Israelite monarchy. This was often based on the promises God makes to David in 2 Sam 7, which state that his son Solomon:

Will build the Temple.
Will become God's son.
Will have a throne established forever.

This makes excellent sense of the fact that the High Priest, in the passage you are asking about, moves directly from questions about Jesus's relationship to the Temple to a question about whether Jesus is God's son: both questions were attempts to determine whether Jesus saw himself as a fulfillment of 2 Sam 7. So when the High Priest asked if Jesus was God's son, he meant, “do you think God has adopted you as a son to rule over his people Israel, like he adopted Solomon as his son?”


How old was Flavian of Constantinople, roughly, when he died?

I assume you are referring to Flavian the Confessor, Patriarch of Constantinople from 446 to 449.

There are a couple of online hagiographies available (e.g. this one from the Orthodox Church in America).  There is a much more detailed description of his life (6 pages) in Sergius of Radonezh' Lives of the Saints, available in English translation from Chrysostom Press (he is commemorated on February 18 in the Slavic churches, February 16th in the Greek).

Unfortunately, the only dates are probably ones you have already found - that he was Patriarch from 446 until 449, when he was martyred.  We do know that at the time he was made Patriarch he was a presbyter at the Great Church of Constantinople (in fact, a skevophylax - responsible for the sacred property of the Church).  I believe that a Church canon arising prior to that time required that one be at least 30 years old before being ordained presbyter, though I haven't been able to find it.

If, in fact, such a canon existed prior to his time, and if he met the canonical age requirement (exceptions seem to be frequent), then the best we can do would be to set an upper bound on his birth year at 416.

I read through St. Sergius account along with accounts in a shorter Greek Synaxiarion and in the even shorter Prologue of Ohrid and neither make any mention of his being old or feeble at the time he was martyred.  Admittedly, this is pretty thin, but perhaps we could assume that he would be no more than 50 years old at his death in 449.  This would place a lower bound of perhaps 399 AD on his birth.

So with virtually no solid information, we surmise that he was born between 399 and 416 AD.


Why does the Litany of Saint Joseph call him "terror of demons"?

St. Joseph is the terror of Demons because all of demons effort is nullified if one seeks refuge to St. Joseph  and also because he is pure, and demons cannot stand against his purity.

Even though there is no official dogmatic pronunciation in this regard by the Catholic church, numerous private revelationsexample and traditions have held that St. Joseph, after his conception, was, through the future merits of Jesus cleansed from the stain of original sin. And also Catholic tradition holds that St. Joseph did not sin all thru his life.ref Satan and his cohort of fallen angels had no success in seducing Joseph. These are not dogmas however and Catholics are not obliged to believe these traditions.

Catholic Online says about why St.Joseph is the Terror of demons:

  Those who turn to Saint Joseph for his powerful intercession and good example do much to keep Satan and the other wholly corrupt devils at bay. In this sense, Joseph is the Terror of Demons because when the friends of Jesus avail themselves of his salutary influence, Saint Joseph is for them a sure protection against the oppressive wiles of the Prince of Darkness. src

One more POV in this regard:

  But evil shrinks from Joseph for He is pure. ... The demons can't "see" Joseph because he is pure. Purity makes him invisible, just as pure water is perfectly clear. Evil spirits don't know when, how, or from which direction Joseph is going to hammer them. Joseph's job, when Christ was a child and up to this very day, is to protect the Holy Family, and through our baptisms, we are part of his family. src


According to Catholic law and rules, is postponing of the Rite of Acceptance OK?

It appears that the difference between the usage in English speaking countries of "Chatechumenate", is the same as the Czech phrase "preparation for Baptism". I note that the Catechism of the Catholic Church says

  1247 Since the beginning of the Church, adult Baptism is the common practice where the proclamation of the Gospel is still new. The catechumenate (preparation for Baptism) therefore occupies an important place. This initiation into Christian faith and life should dispose the catechumen to receive the gift of God in Baptism, Confirmation, and the Eucharist.

So, I would say the answer to your question about a about a liturgical rule delaying baptism is a modified "yes". The need for an adult candidate for Baptism to be properly prepared for the Sacrament, and understand what it means to him, and requires from him, in most cases necessitates a delay to permit that to occur. But it also appears from the Catechism that there is an expectation that the delay be as short as possible, and I understand that it can be waived in some circumstances, for example, in the case of a person who is very near to death who has not been, and desires to be baptized.


Does Eastern Orthodoxy approve the use of contraception?

According to the Orthodox Church In America contraception is only permitted when danger or hardship would come to the family as a result of birth of a child as seen here on their website

  The voluntary control of birth in marriage is only permissible, according to the essence of a spiritual life, when the birth of a child will bring danger and hardship. Those who are living the spiritual life will come to the decision not to bear children only with sorrow, and will do so before God, with prayers for guidance and mercy. It will not be a decision taken lightly or for self-indulgent reasons.
  According to the common teaching in the Orthodox Church, when such a decision is taken before God, the means of its implementation are arbitrary. There are, in the Orthodox opinion, no means of controlling birth in marriage which are better or more acceptable than others. All means are equally sad and distressing for those who truly love. For the Christian marriage is the one that abounds with as many new children as possible.


So, apparently (or at least according to a deacon who is citing a canon lawyer), Canon law would say that my parent's marriage was putative and, as such, I can be considered a legitimate son.


I would propose the following criteria for selecting an English Bible translation:

faithfulness to the original languages
translation philosophy (thought-for-thought, word-for-word, or paraphrase)
usage of the best texts/manuscripts available
readability

These criteria are purely subjective, therefore some theological traditions will prefer various manuscripts or translation philosophies over others.

Faithfulness to the original languages

Is the translation based on the original Hebrew, Aramaic, and Greek manuscripts? Or is it based on an existing translation? Is the translation consistent? Does it take recent scholarly linguistic and philological data into account? Does it allow the New Testament to inform how the Old Testament is translated? Are masculine pronouns translated as gender-neutral where grammar allows? Is there a clear theological bias (translations produced by sectarian groups or individuals often have a determined bias).

Translation philosophy

A thought-for-thought translation is known as dynamic equivalent, while a word-for-word translation is called formal equivalent. A paraphrase involves restating the meaning of a given passage in other words. Essentially this is a metric of how literal a translation is (does it follow form or meaning?). Remember that both form and meaning can be important; this is a subjective decision (just like all of the other criteria).

Usage of the best texts/manuscripts available

Some theological traditions have defined manuscripts/texts that are to be considered authoritative. Others tend to trust certain "families" of manuscripts more than others (Byzantine/Majority vs. Alexandrian, etc.). Others would prefer critical texts produced with the best quality scholarship that take early translations and manuscript variants into account.

Readability

This criteria is often overlooked. There is some truth to the old saying that "the best Bible translation is the one you read." Who cares how well it meets the other criteria if you can't comprehend what you're reading? Some translations are harder to read than others.

The best translation is a purely subjective choice that factors in these criteria. Some may consider certain criteria to be more important than others, while others may wish to balance all of them equally.


Historically what percentage of the Catholic Church's liturgical function was done in Latin?

The Holy Sacrifice of the Mass: Dogmatically, Liturgically and Ascetically Explained (1902) by Fr. Nikolaus Gihr writes in the first footnote of §32, "The Language Used in the Celebration of the Holy Mass" (p. 319-328):

  Whether the Apostles celebrated the Holy Sacrifice in the language of each individual nation or only in the Aramean (Syro-Chaldaic), Greek and Latin languages cannot be determined with certainty. In any case, from the first four centuries no liturgy can be shown composed in any other than the three languages of the inscription of the Cross [i.e., Hebrew, Greek, Latin]. In the West, for example, in Italy, in Germany, in Spain, in France, in England, Latin was at all times the liturgical language. Toward the end of the ninth century Pope John VIII. (872-882) permitted the Moravian Slavs, converted by Sts. Cyril and Methodius, to celebrate the liturgy in their (Slavonic or Glagolitic) native language, and that probably in order to prevent their apostasy to the Greek Schism. In the East also the Church later on permitted some schismatics and heretics, who had returned to the unity of the Church (for instance, the Copts, Armenians, Ethiopians), to retain their native language in the liturgy.

Fr. Adrian Fortescue's 1917 The Mass: A Study in the Roman Liturgy says, in §3 "Latin as a Liturgical Language" of the ch. "The Origin of the Roman Rite," that (p. 126-127):

  Latin was apparently first used by Christians in Africa. Pope Victor I (190-202), who was an African, is generally quoted as the first Roman to use it.³ Novatian (c. 251) writes in Latin; since about the third century this becomes the usual and then the only language spoken by Christians at Rome. When it replaced Greek in Church is disputed. Kattenbusch dates it as the liturgical the second half of the third century,⁴ Watterich,⁵ Probst⁶ and Rietschel⁷ think that Greek was used till the end of the fourth century. In any case the process was a gradual one. Both languages must have beenused side by side during a fairly long period of transition. A certain Marius Victorinus Africanus, writin about 360 in Latin, still quotes a liturgical prayer in Greek.¹ The Bible existed only in the Greek Septuagint for some time.² The lessons were read in Greek at Rome, at any rate on some days, till the VIIIth century;³ some psalms were sung in Greek at the same time.⁴ Amalarius of Metz⁵ († c. 857) and Pseudo-Alcuin⁶ still mention Greek forms. The creed at baptism may be said in either Greek or Latin, at the convert's discretion, according to the Gelasian Sacramentary.⁷ But our present Greek fragments⁸ are later interpolations.

By at least the 12th century, the Latin language in the Roman (i.e., Latin) Rite was most widely used, and, as Fr. Gihr writes (p. 319-320), it was attacked by heretics and schismatics:

  The Mass considered in itself could assuredly be celebrated in any language, but by the Providence of God the Latin language has become, and still continues to be of all languages the most widely diffused for divine worship.² The very ancient practice of the Church of celebrating Mass in the West, not in the living language of the country, but in a dead language, that is, in Latin, for the most part a language unintelligible to the people, has since the twelfth century to the present epoch been frequently made the subject of attack.

Between the 12th century and the Council of Trent, there were some oddities or abuses like half-Latin, half-vernacular sequences (cf. Fortescue p. 275), but the Council of Trent curtailed these by saying (Session 22, can. 9):

  Canon IX.—If anyone saith, … that the mass ought to be celebrated in the vulgar tongue only… let him be anathema.

Regarding homilies: These are meant for the instruction of the faithful, and thus they were in the vernacular.

For the most recent scholarship on this topic, see:

Reid, Alcuin. The Organic Development of the Liturgy: The Principles of Liturgical Reform and Their Relation to the Twentieth Century Liturgical Movement prior to the Second Vatican Council (Farnborough, Hants.: St. Michael’s Abbey Press, 2004).

International Federation Una Voce (FIUV)'s position paper:

PP 7: Latin as Liturgical Language (revised 10/10/12)

FIUV is an international organization promoting the pre-Vatican II Roman Rite Mass in Latin.


Why didn't God reveal all the answers to life?

It is the glory of God to conceal a matter; to search out a matter is the glory of kings. (Proverbs 25:2, NIV)

There's a sense in which mysteries bring glory to God and solving them bring glory to us. It's no accident that so many people enjoy puzzles and riddles or exploration and experimentation, it's just another way in which we reflect the God whose image we are made in.


Does there exist within the Catholic Church a church, cathedral or even an altar dedicated to the Holy Spirit?

There are some churches dedicated to the Holy Spirit in Poland:
Google Maps
Exclude the westmost one - Armenian (not catholic) and the eastmost one - Orthodox.
Translation help (in case the map still shows Polish labels) - English to Polish:
church - kościół
of the Holy Spirit - Świętego Ducha/Ducha Świętego (the ordering of words is not that important in Polish due to extensive declination of nouns - 7 cases)
EDIT: The churches on the map are all Roman Catholic except for the 2 mentioned above. 95% of Polish citizens declare Roman Catholic faith. Most of them are not participating in religious practices but that's a different story. You may only find Protestant churches in bigger cities and some relatively small areas close to borders with Czechia and Germany. Orthodox churches are also present only in bigger cities and areas close to the eastern border with Ukraine, Belarus, Lithuania and Russia.


What differences will being a Christian make in this life?

I'm not sure what you mean by "on a personal scale".

Being a Christian can (should!) change oneself to model oneself more closely on Christ and follow his teachings.

It can also affect others on a personal scale: William Booth and Edith Cavell are two modern examples who come immediately to mind, but there are many, many more stretching back into antiquity (for example, monastic orders who provided education and healthcare).

It's not simply a group identity as you propose, although of course there is the sure and certain hope of resurrection to new life. However, even if someone should like the idea of Heaven in the next life, or feel there should be more to this present life than they have, it's my experience that investigating that by joining a congregation will convince them of what it is to know Christ and that is their entry to Heaven. That sounds really evangelical; but I'm Roman Catholic.

This probably won't be sufficient. Could you expand on your question?


Where does Jesus stand on war and peace?

This is not about war, as in killing people, but about the coming struggle to bring people into the Christian faith, when the faith will deny their previous beliefs, whether Jewish or Pagan. Jesus is likening the struggle to spread the faith to a war. I believe this interpretation is pretty much universal to all denominations.

This verse is sometimes cited by non-Christians as evidence that Jesus was a historical  militaristic guy, like Bar-Kochva. This is just not a reasonable interpretation.


When did the African-American population become Christian?

Pretty much the classic study of the African-American Church in America is E. Franklin Frazier's 1964 The History of the Negro Church in America.  Indeed, its popularity can be evidenced by another book, The History of the Black Church since Frazier.

In a nutshell, the history of the black church in the United States is what you'd expect:

Slaves were brought over
They were taught Christianity

What was unexpected was what happened next:
During the Great Awakening, the church grew
Blacks made the church their own
Christians, seeing other Christians not being treated Christian, changed the culture at large.

The interesting part of the story is the motivation and whether the movement was "forced" upon Blacks or whether it was a blessing coopted by them.

Ever since 1619, when African slaves were imported to Jamestown, the slaves were the nucleus of Christian training and education.  The cynical will say it was a means of controlling the population, and the sociologist may argue that the church was written onto the cultural tabula rasa that arose in the absence of any other common tradition or language. (Per Frazier, the American slave population was drawn from the vastly different regions of the slave coast, and thus there was no single common identity from the Old World.)  And, to be sure, there were "purer" motives of "saving the heathens" - both paternalistic and out of genuine concern.

A modern missiologist, however, would most likely argue that the history of the black church is the history of Joseph - what [we] intended for evil, God used to work for good. Indeed, Frazier argues the church rose as much for economic motives (replacing the tribal cultural an massing the strength of the African American community) as religious ones.

But to merely ascribe the rise of the church to "population control" motives misses out on the fact that the black population truly made the church their own is to do African Americans a major disservice. The story of Richard Allen, Absalom Jones and the rise of the AME church, for example, shows that it was not something "forced" upon them.  In the 1780s's, Jones and Allen led a black congregation that met in St. George's Church in Philadelphia in the early morning. Jealous of the success of that church, the white vestry that owned the building made life progressively more difficult, culminating in an episode in which Allen, in the midst of leading prayer, was savagely beaten at the altar.  His congregation moved out and later helped nurse Philadelphia through an outbreak of yellow fever - in spite of the opposition of the establishment.

As to the amazing rise of the church, it should be remembered that much of the slave trade - muchly stopped by the British who made it illegal to transport slaves across the Atlantic in 1808 - coincided with the First and Second Great Awakenings of the 1700s.  The fact that most African Americans today are Methodist and Baptist is indicative of that fact.  (Remember, they were imported into a colony - my own Virginia - that was strictly Episcopalian, and the "E" in AME is Episcopalian, but that "M" is Methodist). The overall rise in religiousity in American culture simply spilled over across racial lines.

I have no argument that slavery was anything less than unmitigated evil. That it was even justified in theological terms (Cursed be Caanan / Gen 10) is reprehensible.  And indeed, if you look at how segregation in churches was the response to the loss of the Civil War, I think it difficult to justify. But, in the same way that God used the sins of Joseph's brothers to glorify Himself, so to the rise the church that was introduced at the lash of the whip came to change the consciousness of the slave owner.  From the Christian Abolitionist movement of the early 1800s to the Civil Rights era of the 1950s (note, there is a reason Rev. Martin Luther King, Jr called it the Southern Christian Leadership Conference, the issue of the "black man" was radically redefined when understood in the light of Jesus. To call the church "forced" upon blacks may have been true for a very short period, but they truly made it their own.


Is there a biblical basis for the division caused by theology?

INTRODUCTION

Your specific question is not overly clear, but it seems you are essentially asking if there is any doctrine worth dividing over, and you mention the many denominations that exist as problematic.

I'm reminded of the satirical quote by Steve Turner:

We believe that all religions are basically the same, at least the one we read was.
They all believe in love and goodness, they only differ on matters of creation, sin,
heaven, hell, God, and salvation.

In short, yes, there are doctrinal differences worth dividing over, and there is, indeed, a biblical basis for this.  Yet, there are also doctrinal differences that are not worth dividing over as well.

An old axiom is instructive at this point:

In Essentials Unity,
In Non-Essentials Liberty,
In All Things Charity.

So, we have to determine what are the essentials and what are the non-essentials.  People will differ on this, but the essentials should probably include 1) the nature of God and 2) the doctrine of salvation at the very least.

ESSENTIALS

Paul wrote his letter to the Galatians to specifically correct heretical doctrine, and he uses some pretty strong language to do so.

  I am amazed that you are so quickly deserting Him who called you by the grace of Christ, for a different gospel; 7 which is really not another; only there are some who are disturbing you and want to distort the gospel of Christ.  Galatians 1:6-7 NASB

Paul continues with strong words against those that had perverted the purity of the gospel:

  But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed! 9 As we have said before, so I say again now, if any man is preaching to you a gospel contrary to what you received, he is to be accursed!  Galatians 1:8-9 NASB

Thus, the purity of the gospel of grace is, indeed, worth dividing over.  Paul preached salvation by grace and not of works and was willing to divide with those who preached a salvation based on law.

NON-ESSENTIALS

Non-essential issues include many things, including church order, musical preference, the use of certain spiritual gifts and other things.  Here in America, we have the luxury of going to the particular church that best aligns with all of our individual idiosyncrasies and personal preferences, yet in many other parts of the world, much more unity is displayed, particularly in places where Christianity is under persecution.  Still, most mature Christians maintain healthy fellowship and unity with those with whom they differ in non-essentials.

CONCLUSION

So, yes, if someone distorts the nature of God or the doctrine of salvation, we should follow the example of Paul and divide over that.  Draw the line in the sand and do not compromise.

Yet, for many other things, we in the West can choose to gather in different buildings and segregate based on peculiar non-essential issues, but we should certainly maintain unity in the faith with all our brothers with whom we can unite in the essentials.


Does the Catholic Church have a position on slavery reparations?

I do not think the Church has any official position, or any reason to have one.
In the link provided, Rev. Farrakhan is quoting a papal bull dating from 1452, that is essentially authorizing the Portuguese king, Alfonso V, to conduct a new crusade against the "Saracens" (probably the Ottoman Empire).
In it, there is a phrase in which the pope authorizes the king as follows:

With these words, by the Apostolic authority, we grant you permission to invade, conquer, capture, and subjugate those persons [the Saracens, unbelievers, and enemies of Christ], and reduce them to perpetual servitude, and also the lands, duchies, counties, principalities, and any other dominions, possessions, and goods of the same (my translation).

Or, see the Latin original:

Invadendi, conquerendi, expugnandi, et subiugandi, illorumque personas in perpetuam servitutem redigendi, regna quoque, Ducatus, Comitatus, Principatus, aliaque Dominia, possessiones, et bona huiusmodi, tibi et successoribus tuis Regibus Portugalliae, perpetuo applicandi, et appropriandi, ac in tuos, et eorundem successorum usus, et utilitates convertendi plenam, et liberam, auctoritate Apostolica, tenore praesentium concedimus facultatem.

Noteworthy is the phrase perpetuam servitutem. It is possible that the pope is authorizing a kind of serfdom, which was still all too common in Europe at the time. The term servitudo is ambiguous. In addition to "slavery," it could be a generic term for "subjugation" or "service."
Pope Nicholas actually uses the term in that way in the opening of the bull:

Dum diversas, nobis licet immeritis superna providentia commissi Apostolicae servitutis officii, curas, quibus quotidie Nos urgentibus angimur, sedula quoque hortatione pulsamur, in mente revolvimus.
As we turn over in our minds the various cares of the duty of Apostolic service, entrusted to us by celestial providence (much as we do not deserve it), by which we are urgently anguished, we are also moved by an insistent encouragement.

Regardless of Rev. Farrakhan's intentions, he does not seem to have been aware that this bull was written nearly a century before the Atlantic slave trade began. It was completely unrelated to the tragic deportation of Africans to the Americas.
That the pope should authorize a crusade of this kind (let alone authorize serfdom for the conquered peoples) is, naturally, an excessive mingling of temporal and spiritual power.
This bull cannot, however, be construed as a teaching or magisterial document. It has no weight whatsoever regarding the Church's teaching about serfdom and slavery, which did not develop until later, in the light of the Atlantic slave trade and the colonization of the Americas.


Do Mainline Presbyterians oppose Satisfaction Theory? Is this why "In Christ Alone" was rejected for their Hymnal?

If you want to understand why the PCUSA's hymn committee rejected the hymn, then you should read its brief statement of faith. The statement of faith focuses heavily on grace, and satisfaction theology tends to focus on works. The line from the song in question is very much based in satisfaction theology and thus contradicts the statement of faith.


According to Old Testament, how long did Saul reign as king?

The variation comes from missing digit(s) in the extant Hebrew manuscripts for 1 Sam 13:1.  Dr. Michael Heiser's 2008 blog article about it, 1 Samuel 13:1 – The Matter of Missing Words in the Bible, summarized the problem well:

The Masoretic Text (MT) literally says “Saul was a son of a year in his reigning and two years he reigned over Israel.” Obviously there are two errors in the Hebrew text as we have it today: (1) Saul was not one year old when he became king, and (2) he reigned more than two years.
The first error is obvious, since the book of 1 Samuel tells us plainly how Saul was chosen and anointed king — and he was a full grown man. The second error is plain when viewed against Acts 13:21 (and when reading the account of Saul’s kingship in the OT).
Now, in one regard, this is no different than any other text-critical problem. You detect the error in the present text, then work to find out how it came about, and consult other manuscripts of the Hebrew Bible for the solution. But there’s the rub — in the case of 1 Sam 13:1, there are no other reliable manuscript readings.

Unfortunately, none of the Dead Sea Scroll fragments related to the Book of Samuel has 1 Sam 13:1.  See 1984 paper Additions or Omissions in the Books of Samuel: The Significant Pluses and Minuses in the Massoretic, LXX and Qumran Texts by Stephen Pisano, S.J.
The entire verse was also missing from earlier copies of the Septuagint.  Some later copies have 30 but deemed as corruption and therefore modern translations of Septuagint omit this verse, such as Chapter 13 of the NETS Septuagint translation.  See Dr. Michael Heiser's blog article referred to above for more discussion on this, as well as this article.
To reflect the missing information some translations, such as the NRSV, render 1 Sam 13:1 as follows:

Saul was . . .  years old when he began to reign; and he reigned . . .  and two years over Israel.

with the footnote:

1 Samuel 13:1 The number is lacking in the Heb text (the verse is lacking in the Septuagint).

Another blog article Rereading 1 Samuel 13:1 by Claude Mariottini, a
Professor of Old Testament at Northern Baptist Seminary provides a good explanation why translations differ:

The different readings for the length of Saul’s reign in the translations are only possibilities.  Thus, if a translation says that Saul was 30, or 40, or 50 years old when he began to reign and then says that he reigned 42, 32, 22, or 2 years over Israel, that translation is not teaching biblical truth but educated possibilities.  The fact is, that since the numbers are contradictory, then one or all of the translations may not be presenting the right information.

In Acts 13:21 we have 40 years, see Acts 13:21, NRSV:

²⁰ ... After that he gave them judges until the time of the prophet Samuel. ²¹ Then they asked for a king; and God gave them Saul son of Kish, a man of the tribe of Benjamin, who reigned for forty years.

Possibly, St. Paul quoted a Septuagint manuscript that is no longer extant.  Or he may have relied on Josephus who said in Antiquities of the Jews — Book VI:

To this his end did Saul come, according to the prophecy of Samuel; because he disobeyed the commands of God about the Amalekites; and on the account of his destroying the family of Ahimelech, the High Priest, with Ahimelech himself; and the city of the High Priests. Now Saul, when he had reigned eighteen years,²² while Samuel was alive; and after his death two, [and twenty,] (35) ended his life in this manner.

Finally, yet another article tries to deduce the reign length of Saul from implications it has on other characters's ages: Judges: The reign-length of Saul.  The article recommends between 10-20 years and instead suggests one possibility: clause placement corruption in Acts 13:21 and that Paul meant it was David who reigned for 40 years.


Is there any Christian teaching as to where Adam and Eve were sent after their fall from the Garden of Eden?

Is there mentioned any exact location where Adam and eve have been sent?

No. And for good reason; the Flood caused massive, catastrophic changes to the world, such that any such information would be meaningless post-Flood.
If one accepts Genesis, then, the question is pointless, because, while the answer might be interesting from a standpoint of pure curiosity for its own sake, it would not have any relevance beyond that.
Safa and Marwa are apparently real places in Saudia Arabia. These places would not have existed pre-Flood; not, at least, in any recognizable form (the land that now comprises them may have existed, but might have been scattered all over the place, or might have been deep beneath the surface of the Earth, or...). Therefore, according to Christians (at least ones that accept the accounts of the Bible), there is no connection between these post-Flood locations and any location that might have been known to Adam and/or Eve, and even claims that the names were recycled (as e.g. the Tigris and Euphrates rivers) are at best suspect because Arabic as a language did not exist until post-Babel.


How do you explain the Christian Message to people who have no Christian vocabulary or context?

This was the original point of "The Four Spiritual Laws. In that scheme:
1. Sin separates us from God
2. We cannot pay for our sin
3. Jesus did pay for that sin by dying on the cross
4. If we trust him, he will take us to heaven.

Even that assessment, however, (substitutionary atonement at its best!) is a bit technical and theological  Below is how I would relate the Gospel to a "newbie" (And note, I am not using them exactly as stated)

You were created to be a good thing, but like all all of us, you haven't lived up to that full potential. None of us is good enough to be what it is that God (the Supreme Being and Creator of all that is) designed us to be. (Gen 1:27, ISA 53:6, Eph 2:10)
Because we are not living up to what God would have us be, there is a penalty- an inability to be with God. Justice demands that as people who fall short of God's glory, we cannot stand in God's presence. (Because God is perfect, and we are not, how could we truly stand to be with someone totally holy? It's like when all those Nazis looked into the Ark of the Covenant and saw the angel of the Lord!  We just aren't strong enough or pure enough to look upon absolute pure holiness. ) (Ex 34:2, Mal 3:2, Rom 3:23, rom 6 &7)
Because of that gap, God realized that he had to make the first step- and here is that good news: that God so loved the world, that even though he was God, he chose to empty himself of being God, in order to find a way that he could both pay that for that penalty, and show us how to live with Him once he returned to his full God-like nature. (John 1, 3:16, Phil 2:5-12)
If we are simply willing to completely trust Him, he is willing to make us fit to stand in his presence, blameless, with great joy! (Prov 3:5-6, Jude 24, 25)
He will cause us to suffer, he will discipline us, and he will command us to do all sorts of things completely contrary to what our"common sense" will tell us to do- but if we completely trust him- if we take Him at his word, we will become his children- heirs in a legal sense. He talks to us through the Bible, through prayer, and by causing things to happen in our lives that force us to learn how to discern his will and lean on him for the strength to do what he would have us do. (Heb 12:1-6, James, Rom 8)
The primary thing that God would have us be is loving. God is love. God desires what is best for us, even if it is not the thing that gives us the most pleasure. He trains us to do the same thing- to love others in the way that he loved us. (Heb 12:1-6, (1 John, 1 Cor 13)


Why were the golden plates necessary if Joseph Smith received his translation of the Book of Mormon by viewing a stone in his hat?

Not even the stones were really necessary, as is clearly shown by the many revelations that came without them.

But: The existence of the seer stone shows that Joseph believed that revelation could come through a physical object. So that helped his faith, but also probably made the translation easier for him, as he had more experience with the stone than "direct revelation". I think we see that change later during the course of his life.

Second: The existence of the plates, even though few people saw them, helped that people believed this was an actual record written by ancient prophets. Also, it provided the opportunity to have the witnesses see the plates and testify for their existence, giving more credibility to Joseph.

Joseph wasn't given the ability to read and understand the plates, and then carry out a translation with this knowledge. He was given the translation directly.


St. Albans Psalter - history of manuscripts used to translate the Psalms

The St Albans Psalter is a unique individual  volume containing the psalms, bound together with some other material. Strictly speaking "psalter" means a copy of the psalms, but is often used to refer to books containing the psalms and other things, in the same way as a "bible" may contain the bible and other material e.g. maps.
The St Albans Psalter was not a new Latin translation of the psalms. The Latin text of the psalms is simply the standard text used in most of Western Europe, though not Rome,at the time. This is known as the Gallican text.
Jochen Bepler, Peter Kidd and Jane Geddes have published avery informative paper called          The Albani Psalter.  It includes the following explanation of the origins of the Gallican text.

From the fifth century three  versions  of  the  Psalms  predominated.  The  version  that  is  now  known  as  the ‘Romanum’ was traditionally thought to be the work of St Jerome, but this is now doubted. He was certainly responsible for three versions of the Psalms, but the first only survives as snippets quoted in other works. After this he produced what is now known as the ‘Gallicanum’ version, which he based on Greek texts (which had them-selves  been  derived  from  Hebrew).  And  finally  he  produced  a  translation  based directly on Hebrew manuscripts, the ‘Hebraicum’ version. The  Romanum  version  of  the  Psalms  was  widely  used  in  Europe  until  the  ninthcentury, and continued in use in Italy until the sixteenth century; it is still used in thebasilicas  of  the  Vatican  and  San  Marco,  Venice.  It  was  also  used  in  English  churches until  the  late  tenth  or  early  eleventh  century.  The  Gallicanum  version  of  the  Psalms became especially popular in Gaul (hence the name), and was adopted for liturgical use, superseding the Romanum version in most places from the ninth century onwards. This is  the  version  that  appears  in  the  ‘Vulgate’  version  of  the  whole  Bible,  found  in  mostmanuscript and printed Latin Bibles from the thirteenth to the twentieth century. The Hebraicum version of the Psalms never found very wide favour, because it was too different from the versions which were already very well known and well established, butit is occasionally found in manuscripts with double or triple versions laid out in parallel columns alongside one or both of the other versions for comparative purposes

Jerome translated what became known as the Gallican from the Greek Septuagint, which in turn was a translation from the Hebrew into Greek.
The scribes who produced the Albani psalms merely copied from other copies. There was no thought of producing a new translation.
I am not aware of the St Alban's psalter, the physical book, per se, being translated into English and still being used today. Miles Coverdale made a translation from the Latin Gallican text into English in the 1530s. In doing this he simply translated from Latin to English. Coverdale's translation can therefore be considered a translation from the text used in the St Alban's Psalter.
Coverdale's psalms were included in the first Book of Common Prayer, in 1549. The 1662 edition replaced all Scripture quotations with those in the King James Bible, with the exception of the psalms. It had been intended to replace the psalms too, but this was objected to because people knew the Coverdale versions, particularly important for congregational singing in an age of linmited literacy. Coverdale's are generally also thought more rhythmical.
Even today the psalms in the Book of Common Prayer are still Coverdale's, and are still used in the Church of England, most commonly at Evensong, though modern versions are authorised as an alternative.
There is no doubt that the KJV, produced by a team of scholars translating from the Hebrew, is much more accurate than the BCP translated by one man from a Latin translation of a Greek translation of the Hebrew.
In the days before football rivalry the English could boast that they chanted the exact words of the psalms whereas the Scots, by using metrical adaptations, were less Bibllical. The Scots on the other hand pointed out that their metrical versions were based on a much more acccurate translation.


Can the ancestral sin doctrine (and Paul's epistles) survive without a single breeding pair?

Preface that this isn't a site for debating what is true, it's merely for learning what s taught/believed within Christianity.  See  How we are different than other sites?

With that in mind, most of your question is off-topic, but I believe that the core concept from your question can be addressed if we phrase it as follows:

Do any Christian groups believe that without a literal Adam, the concept of original sin has no meaning?

I'm going to answer that portion, in the interest of answering the heart of the question, filtering out the portions that are off-topic and/or controversial/disputed within Christian circles.

The short answer is tat yes, some Christians, namely Young-Earth Creationists teach and believe exactly that.  Ken Ham, Kent Hovind and other well-known YEC proponents teach exactly that.

One such example from CCEL

  Is it important:

  Well, if there was no first Adam, could there also not be a second
  Adam, our LORD Jesus Christ? For as in Adam all die, even so in Christ
  shall all be made alive...it is written, The first man Adam was made a
  living soul; the last Adam was made a quickening spirit." 1
  Corinthians 15

  If death did not come as result of Adam's sin, then why did we need a
  savior to deliver us from death unto life? "Just as sin entered the
  world through one man (Adam), and death through sin, and in this way
  death came to all men, because all sinned"- Romans 5

  Was Jesus' real if his geneaology account is not trustworthy? Jesus
  was the son of Joseph, who was the son of ..., the son of Seth, the
  son of Adam (Luke 3) - Can the Word of God be trusted for its specific
  geneaology or is it mythology?

I also posted on the subject at Why do Young-Earth Creationists make such a big deal about the YEC view.

Not all Christians see it thus way, of course.  This represents only one view within Christianity.


What cautionary advice have evangelists given that address Gandhi's concern about "Rice Christians"?

Rice Christians. Maybe Gandhi should have said Beef Christians.
I mean, I cried too when Pi killed the fish. [slipped-out]

Unfortunately or fortunately the Word of God is book of human-action,
unlike a calculus math book. Searching for facs/truth...

About "Rice Christians",
1) Christ Jesus healed many people,
which is recorded on the gospels of the new testament.
2) Christ Jesus helped anyone, Matthew 11:28,
"Come to me, all you who are weary and burdened, and I will give you rest."
3) Not all who were helped said thanks, Luke 17:17
4) Nor all who were helped became Disciples, only about 120 left in Acts 1:15
Basically He came to give hoping the ones he helped would repent, Romans 2:4

About Culture Shock, the problem is Christ Jesus said in Matthew 28:19,
"... make Disciples of all nations". Which can cause kaos like you said.
So, Disciples of Christ Jesus make disciples everywhere like in Asia
and give [rest] to anyone [who is weary]. So I think.

About [pouring abuse on Hindus], well this about what someone/somebody did or say.
However, Romans 2:1-4 helps to point out that passing judgment comes around.

If I ever find a Disciple of Christ Jesus,
I would ask for a bowl of rice or two also :)
Thanks for reading.


A collection of information on him is here, some of it is kergyma (oral tradition): http://orthodoxwiki.org/Apostle_Luke

The first paragraph reads:

  The holy, glorious and all-laudable Apostle and Evangelist Luke is the
  author of the Gospel of Luke, the companion of the Apostle Paul (Phil
  1:24, 2 Tim 4:10-11), and is numbered among the Seventy Apostles. He
  was a native of Syrian Antioch and a physician, and is the founder of
  iconography.

According to tradition, he painted the first icon as we think of them, it is called 'Directress' and it is of the Theotokos (Mother of God) holding the child Christ.


Does 'no more room in the Inn' mean spare room not big enough for a birth?

Since it is not in the Bible stable is not essential. But your implication of it is wrong. Just because Jesus was not born in a stable, it does not mean he was from middle class.

First, Middle class did not exist at Jesus's time.

Secondly Luke 2:7 says that he was laid in a manger. Some scholars claim that in those days families had animals inside their home to protect them in winter. It is very unlikely they were kept in the main room. So for Mary to have access to a manger she should have given birth in the portion where animals were kept (this may not necessarily be a stable).

It is not a usual practice to place new born in a manger. And that is why it is given as a sign for the shepherds. Also the host lives in the main room, so a pregnant women who is expected to go into labor anytime would not have any privacy in there.

It is very logical to assume that Jesus was not born in the main room but where animals stay.

Finally think about this: God has eternity to plan his birth. But he choose to be laid on a manger. That is enough sign on the importance he gave for poverty.


Use of "Ontological"

Are the Father, the Son and the Holy Spirit ontologically independent
entities, each one being particulars of universal divine attributes?

The word "ontological" is somewhat up for interpretation, so it's difficult to give a clear answer one way or the other without some clarification. With that said, you will find the word "ontological" used in this context. A distinction is made between Trinitarian theologies which posit an Ontological (a.k.a. Immanent) Trinity, versus an Economic Trinity (Lee, 2009). An Ontological Trinity can be found Niceno-Constantinopolitan Creed, which for example states Christ is

Light of Light, very God of very God, begotten, not made,
consubstantial with the Father

The word "consubstantial" here being a translation of the Greek homoousios/ὁμοούσιος. This is almost always considered to be an ontological statement about Christ's being, or substance, or something along those lines. For example, the English Language Liturgical Consultation renders this "of one Being with the Father". Murray, 1966 does not hesitate to refer to the Nicene creed's approach as "ontological".
Blumell, 2014 writes on p. 197:

the primary focus of
the [First Nicene] council had to do with delineating the proper ontological relationship between
the Father and the Son as it pertained to the Son’s divinity. More specifically, the
council sought to articulate exactly how Jesus ought to be considered divine and,
as such, how he ought to be viewed in relation to the Father.

and on p. 205:

To stress the ontological uniformity of Jesus and the Father the term homoousios (Grk. ὁμοούσιος; Lat. consubstantialis), commonly translated as “same substance” or “consubstantial,” was incorporated into the creed.

Bear in mind that this kind of philosophical terminology unfortunately has a tendency to be a bit nebulous and subject to semantic drift. But it's fairly well-established that these terms of subtance, essence, being, etc. are ontological in character.
The Athanasian Creed, which you mention, is full of statements which can be taken to be ontological, e.g.:

And the catholic faith is this: that we worship one God in Trinity, and Trinity in Unity; neither confounding the Persons, nor dividing the Essence.

In short, Nicene Christianity would almost certainly not hesitate to answer that the Father the Son and the Holy Spirit are not ontologically independent entities, but a single Godhead-entity. In Western Christianity, even more-so in light of the doctrine of Divine Simplicity.
Polytheism, "sub-entities"?

If so, wouldn't that mean 3 Gods instead of 1 God? Or should we
understand God as one entity comprised of 3 "sub-entities"?

Yes, I think you're right to say that if the three persons were ontologically independent, then it would be difficult to avoid the charge of polytheism (since separate ontologies implies that they are separate Gods). That's why Nicene Christianity would rather affirm the ontological unity of the three persons.
As for understanding God as having "sub-entities", that is probably misleading, since it would suggest a divided Trinity. For example, the Fourth Lateran (Roman Catholic) Council taught (On the error of Abbot Joachim):

But it cannot be said that He (the Father) has given a part of His
substance to Him (the Son), and retained a part for Himself, since the
substance of the Father is indivisible, namely, simple.

... the Father and the Son have the same substance, and so this same reality is the Father and the Son and also the Holy Spirit proceeding from both.

The three trinitarian persons under the Nicene view are each fully God, and do not separately need to "come together" to achieve full divinity. God is one entity/being, in three persons. Language of "person" rather than "sub-entity" is the distinction here: "sub-entity" implying some kind of allocation of parts of the greater entity to the smaller parts (which would be contrary to Nicene theology), whereas "person" emphasizing relationships and mutual-Love, etc.
But what does it mean to "be God"?

But then what would it mean that "the Father is God", "the Son is
God", "the Holy Spirit is God"? What does it mean ontologically that
"X is God" according to Trinitarianism?

Trinitarianism is not a monolith, but generally speaking, Nicene Christianity would allow "X is God" to be crudely equivalent to "X is God in substance/being/essence/etc."
I suppose the critical question is how one can say "X is God" and also "Y is God" but not "X is Y". Put in other terms, how can multiple persons each be God, without "confounding the Persons, nor dividing the Essence"? But that is not a question of philosophical coherence, but the statement of a mystery.

Is "Lord" being used here as an entity, as a predicate over entities,
or what?

Lord is a personal title, which arguably means it only makes sense when applied to persons. A chair is not a person (at least, not without a very unusual idea of personhood), so it wouldn't make any sense to say "This chair is my Lord". Regardless of what you think about that argument, Trinitarianism certainly holds that "the Father", "the Son", and "the Holy Spirit" refer to persons, so the predicate is plainly over persons in this case.
Usually, there is only one person per entity. Trinitarianism supposes an exception for God.
Conclusion

What is a formal ontological definition of the nature of God according
to the doctrine of the Trinity?

Expecting an explicit "definition" from official sources is probably too much, although the Athanasian creed is close. Succinctly, God is a single being ontologically, but at the same time, three persons. Each person does not have a separate ontology but shares the one Godhead-ontology.
References:
Lee, S. G. (2009). The Relationship between the Ontological Trinity and the Economic Trinity, Journal of Reformed Theology, 3(1), 90-107. DOI: https://doi.org/10.1163/156973109X403741 Download: https://www.researchgate.net/publication/233714991_The_Relationship_between_the_Ontological_Trinity_and_the_Economic_Trinity
Murray, J. C. (1966). The Status of the Nicene Creed as Dogma., Chicago Studies: An Archdiocesan Review, 5. Text: https://www.library.georgetown.edu/woodstock/murray/1966j#2
Blumell, L. H. (2014). Rereading the Council of Nicaea and
Its Creed. Published in Standing Apart:  Mormon Historical Consciousness
and the Concept of Apostasy, Oxford University Press, pp. 196-217.


Is Christian mysticism an oxymoron or is it a legitimate path for a Christian?

Christian Mysticism has a long and honourable tradition. You can read the histories of many holy Christian mystics. Wikipedia will give you a good starting point. Meditation is only one aspect. For a working definition, try: ""that part, or element, or Christian belief and practice that concerns the preparation for, the consciousness of, and the effect of [...] a direct and transformative presence of [the Christian] God" (Bernard McGinn). In effect mystics are those who make real and experience for themselves things that many Christians take as theoretical or abstract - e.g. the presence of God, union with God, the indwelling of the Holy Spirit.

Here are some well-know people and practices that form part of the Christian Mystic tradition:

Spiritual Exercises of St. Ignatius Loyola
Meister Eckhart
Brother Lawrence
Julian of Norwich
Teresa of Avila
St John of the Cross
Thomas Merton


Is it true that Luther claimed Popes and priests commonly practiced sodomy?

Actually, surprisingly,  Luther did think this and did make this accusation.  Luther made John the Baptist's accusation against Herod's adultery seem trivial compared to the corruption of the Roman clergy. Clearly he accused the Roman clergy of practicing sodomy:

I am not lying to you. Whoever has been in Rome knows that conditions are unfortunately worse there than anyone can say or believe. When the last Lateran council was to be concluded in Rome under Pope Leo, among other articles it was decreed that one must believe the soul to be immortal. From this one may gather that they make eternal life an object of sheer mockery and contempt. In this way they confess that it is a common belief among them that there is no eternal life, but that they now wish to proclaim this by means of a bull. More remarkable yet, in the same bull they decided that a cardinal should not keep as many boys in the future. However, Pope Leo commanded that this be deleted; otherwise it would have been spread throughout the whole world how openly and shamelessly the pope and the cardinals in Rome practice sodomy. I do not wish to mention the pope, but since the knaves will not repent, but condemn the gospel, blaspheme and revile God’s word, and excuse their vices, they, in turn, will have to take a whiff of their own terrible filth. This vice is so prevalent among them that recently a pope caused his own death by means of this sin and vice.In fact, he died on the spot. All right now, you popes, cardinals, papists, spiritual lords, keep on persecuting God’s word and defending your doctrine and your churches!
No pope, cardinal, bishop, doctor, priest, monk, or nun will condemn such an obviously disgraceful life; rather they laugh about it, excuse it, and gloss over it. They incite kings, princes, country, and people to defend such knaves with life and property, with land and people, and faithfully to protect them so that such vices might not be repented of and reformed, but rather strengthened, sanctioned, and approved. Now you are to hazard blood, body, and life just for the sake of Saddling your neck and conscience with this. I could easily mention more examples of such abominations, but it is too shameful; I fear that our German soil would have to tremble before it. But if an impudent popish ass should come along and dispute this, he will find me ready to do him battle, and it will be quite a battle!  (Luther's Works Volume 47, P38)

It appears that he thought this practice was related to the forced abstinence that the priests and Pope had to bear:

There Is Danger in Avoiding Marriage May 29, 1539
Thereupon there was conversation about the delightful institution of marriage. [Martin Luther said,] “Through the papists Satan so defiled it that in his little book on the celibacy of priests Cyprian wrote, ‘If you hear a woman speak, flee from her as if she were a hissing snake.’ That’s the way it is. When one is afraid of whores one must fall into Sodomite depravity, as almost happened to St. Jerome.   ( Luther's Works Volume 54, P357)


According to lds.org:

  As members of The Church of Jesus Christ of Latter-day Saints, we are blessed to be led by living prophets—inspired men called to speak for the Lord, as did Moses, Isaiah, Peter, Paul, Nephi, Mormon, and other prophets of the scriptures. We sustain the President of the Church as prophet, seer, and revelator—the only person on the earth who receives revelation to guide the entire Church. We also sustain the counselors in the First Presidency and the members of the Quorum of the Twelve Apostles as prophets, seers, and revelators.

It appears that, instead of being the last, Joseph Smith is considered to be the first in a long line of modern-day prophets.


How is the Catholic belief in Purgatory supported?

Some background: what Purgatory is, and what it is not
Before answering the question, it is necessary to understand exactly what the Church means by “Purgatory.” The Catechism of the Catholic Church (CCC) says the following:

1030. All who die in God's grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of heaven.
1031. The Church gives the name Purgatory to this final purification of the elect, which is entirely different from the punishment of the damned. The Church formulated her doctrine of faith on Purgatory especially at the Councils of Florence and Trent. The tradition of the Church, by reference to certain texts of Scripture, speaks of a cleansing fire:

As for certain lesser faults, we must believe that, before the Final Judgment, there is a purifying fire. He who is truth says that whoever utters blasphemy against the Holy Spirit will be pardoned neither in this age nor in the age to come. From this sentence we understand that certain offenses can be forgiven in this age, but certain others in the age to come [a quotation from St. Gregory the Great, Dial. 4,39:PL 77,396, with a reference to Mt. 12:31].

Hence, Purgatory is a temporary state that allows souls that die in friendship with God, and yet are still have some of the effects of sin in their soul, to be cleansed before their definitive encounter with God. This cleansing (which may take place on earth, in the form of reparation, or after death in Purgatory) constitutes the “temporal punishment” that is is the consequence of committing offences against God.
It is absolutely not, therefore, a “miniature Hell,” nor is it an intermediate state “between” Heaven and Hell. All souls in Purgatory are assured of their salvation; they are guaranteed to be in Heaven one day.
The Church teaches that it is the duty and a work of mercy for Christians to pray for the souls being cleansed after death—and this is the justification for indulgences (remittance of the temporal punishment due to sin) that are applied to the deceased (see CCC 1032).
Many sources speak of a “purifying fire,” including the text from St. Gregory above, but we must stress that the “fire” in question is strictly metaphorical, since the persons in Purgatory are still waiting for the Resurrection of the Body. (Hence the fanciful depictions of Purgatory in works such as the Purgatorio in Dante’s Divine Comedy must be regarded as metaphorical, and often, as simply inaccurate.)
(Another common misconception is that persons spend a certain amount of “time” in Purgatory, and that the prayers and indulgences reduce or eliminate that “time.” This misconception has doubtless been fostered in part by the fact that before the current Enchiridion on Indulgences, indulgences were often given with a number of “days” or “years;” however, the time period was intended to indicate, not the amount of time remitted in Purgatory, but the duration of certain penances that were traditionally given back in the Middle Ages—indulgences were originally intended to be remissions of all or part of those penances. In fact, since the persons in Purgatory do not yet have bodies—having lost theirs at death and since they are awaiting General Resurrection—they do not experience time in the same way we do on earth. A more severe purification need not, therefore, take place over a longer period of “time.”)
Biblical basis for Purgatory
Although this question has been dealt with in What is the Biblical support for Purgatory?, for the reader’s convenience, here are the passages that the Church refers to:
First, there is 2 Macc. 12:39-45:

39 On the next day, as by that time it had become necessary, Judas and his men went to take up the bodies of the fallen and to bring them back to lie with their kinsmen in the sepulchres of their fathers. 40 Then under the tunic of every one of the dead they found sacred tokens of the idols of Jam′nia, which the law forbids the Jews to wear. And it became clear to all that this was why these men had fallen. 41 So they all blessed the ways of the Lord, the righteous Judge, who reveals the things that are hidden; 42 and they turned to prayer, beseeching that the sin which had been committed might be wholly blotted out. And the noble Judas exhorted the people to keep themselves free from sin, for they had seen with their own eyes what had happened because of the sin of those who had fallen. 43 He also took up a collection, man by man, to the amount of two thousand drachmas of silver, and sent it to Jerusalem to provide for a sin offering. In doing this he acted very well and honorably, taking account of the resurrection. 44 For if he were not expecting that those who had fallen would rise again, it would have been superfluous and foolish to pray for the dead. 45 But if he was looking to the splendid reward that is laid up for those who fall asleep in godliness, it was a holy and pious thought. Therefore he made atonement for the dead, that they might be delivered from their sin (RSV-CE).

It should be pointed out that Catholics (and Orthodox) regard 1 and 2 Maccabees to be part of the Canon of Scripture, whereas most Protestant denominations do not. Catholics and Orthodox, therefore, consider these books to be the inspired Word of God, and hence must accept clear teaching of doctrine, as in Verse 45, as binding.  However, regardless of whether one considers the Books of the Maccabees canonical, they give clear evidence that mainstream Jews in the second century B.C.—at least those who accepted the Resurrection of the Body—routinely made prayers for the dead, a practice that doubtless passed into the early Church. Since prayers cannot help either those in Heaven (because they are already enjoying their definitive encounter with God) or in Hell (because they are eternally deprived of that encounter), it is reasonable to posit a state of purification that occurs after death, for those who need it before they enter Heaven.
Perhaps even clearer than 2 Maccabees is 1 Corinthians 3:12-15 (a text whose canonicity no mainstream Christian denomination disputes):

12 Now if any one builds on the foundation [i.e., Jesus Christ] with gold, silver, precious stones, wood, hay, stubble— 13 each man’s work will become manifest; for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each one has done. 14 If the work which any man has built on the foundation survives, he will receive a reward. 15 If any man’s work is burned up, he will suffer loss, though he himself will be saved, but only as through fire (RSV-CE).

St. Paul in this passage is speaking of the Day of the Lord: a reference to an image dear to many of the Old Testament prophets; in the Prophets, the Day of the Lord refers to moments when God enacts judgment: either on Israel itself, or on her enemies, or else (especially in the later prophets) the judgment that people will receive when they die, or else at the General Resurrection. Here, clearly Paul means the judgment that people will receive after death.
Paul teaches that after death each person’s works (meaning the actions and habits that each person has done during his life) are tested by fire. Those that are enduring (those done in cooperation with the grace of God) survive the test; those that are not (the lingering effects of sinful acts, or acts done without the help of God’s grace) will perish.
It should be noted that this test by fire is not the same as the judgment that determines whether a person will go to Heaven or to Hell: Paul is clearly speaking of those who “will be saved,” although for those with works of straw, “as through fire.” These are all persons who have died in friendship with God, some of whom, however, need a cleansing of their works of straw before they are saved (that is, before they make their definitive encounter with God).
The passage from 1 Corinthians is by far the most explicit; there is also Mt. 5:25-26:

25 Make friends quickly with your accuser, while you are going with him to court, lest your accuser hand you over to the judge, and the judge to the guard, and you be put in prison; 26 truly, I say to you, you will never get out till you have paid the last penny (RSV-CE).

This passage is not, of course, a definitive proof of the existence of Purgatory, but that is certainly a possible interpretation. Coming, as it does, in the Sermon on the Mount, it lends itself to a reflection on the judgment after death. The allegory would be as follows: the time we have on earth is our journey to the courthouse; the “accuser” would be God; and the trial, the judgment we receive at death. We can “make friends” with God now, or else pay the “penalty” in “prison” (i.e., after death). Jesus seems to suggest that the “prison term” is finite—it only lasts as long as there is a “debt” to pay.
A historical argument
The early Christians were fiercely defensive of the true doctrine, and whenever a serious deviation was introduced, there was a swift reaction by those who maintained the orthodox view: this attitude is evident in the various controversies that arose in the first centuries: Marcion (who led a Gnostic sect), Sabelius (who advocated Modalism, a Trinitarian heresy), Arius (who denied the divinity of the Word), the “Pneumatomachoi” (who denied the divinity of the Holy Spirit), Nestorius (who denied the personal unity of Jesus), and so on—there are countless examples.  We would expect that if the doctrine of Purgatory were seen as innovative and dangerous, that there would have been a vocal reaction on the part of the Church; however, there was not. The practice of praying for the dead was uncontroversial (and indeed predates Christianity, as we saw with the passage from 2 Maccabees), as was the idea that a purification is sometimes necessary before persons enter Heaven (already taught by St. Paul, as we saw).
On the contrary, no one, not even the leaders of “heretical” sects (Sabellians, Arians, Montanists, Novatians, and so on) seems to have doubted that idea, which explains why it is not dealt with systematically by the Fathers. Nevertheless, there is a continuous history of belief in such a purification and the need to pray for those persons undergoing it.
The Tradition regarding Purgatory
I reproduce some passages, which I have taken from the article “The Roots of Purgatory” by Catholic Answers.
Texts that bear witness to belief in Purgatory
The following texts are not by Church Fathers, but they bear witness to the fact that mainstream, orthodox Christians believed in a purification after death (i.e., Purgatory), as early as the second century A.D.:

And after the exhibition, Tryphaena again received her [Thecla]. For her daughter Falconilla had died, and said to her in a dream: ‘Mother, you shall have this stranger Thecla in my place, in order that she may pray concerning me, and that I may be transferred to the place of the righteous’ (Acts of Paul and Thecla [A.D. 160], emphasis added).
The citizen of a prominent city, I erected this while I lived, that I might have a resting place for my body. Abercius is my name, a disciple of the chaste Shepherd who feeds his sheep on the mountains and in the fields, who has great eyes surveying everywhere, who taught me the faithful writings of life. Standing by, I, Abercius, ordered this to be inscribed: ‘Truly, I was in my seventy-second year. May everyone who is in accord with this and who understands it pray for Abercius’ (Epitaph of Abercius [A.D. 190], emphasis added).

Here is a text from the Acts of the Martyrdom of Perpetua and Felicity, martyrs from the city of Rome itself.

[T]hat very night, this was shown to me in a vision: I [Perpetua] saw Dinocrates going out from a gloomy place, where also there were several others, and he was parched and very thirsty, with a filthy countenance and pallid color, and the wound on his face which he had when he died. This Dinocrates had been my brother after the flesh, seven years of age, who died miserably with disease. […] For him I had made my prayer, and between him and me there was a large interval, so that neither of us could approach to the other. […] and [I] knew that my brother was in suffering. But I trusted that my prayer would bring help to his suffering; and I prayed for him every day until we passed over into the prison of the camp, for we were to fight in the camp-show. Then […] I made my prayer for my brother day and night, groaning and weeping that he might be granted to me. Then, on the day on which we remained in fetters, this was shown to me: I saw that the place which I had formerly observed to be in gloom was now bright; and Dinocrates, with a clean body well clad, was finding refreshment, […] he went away from the water to play joyously, after the manner of children, and I awoke. Then I understood that he was translated from the place of punishment (The Martyrdom of Perpetua and Felicity 2:3–4 [A.D. 202], emphasis added).

Witnesses from Church Fathers and ecclesiastical writers
The first couple of texts are from Tertullian. He is not exactly a Church Father (he joined a rigoristic sect called the Montanists in the latter part of his life), but he is an important witness to the beliefs of the Church in the early third century A.D.
The first is from De corona (On the crown), which discusses martyrdom. In Chapter 3—which, interestingly, is a justification of the practices of Christians that are handed down as tradition—he notes that

As often as the anniversary [of a person’s death] comes round, we make offerings for the dead as birthday honours (De corona 3:3 [A.D. 211]).

He cites this as an example of something unobjectionable that has been a constant custom among Christians.
In a similar vein, in his De monogamia (On Monogamy), he says

Indeed, she [a Christian widow] prays for his [her husband’s] soul, and requests refreshment for him meanwhile, and fellowship with him in the first resurrection; and she offers her offering on the anniversaries of his falling asleep (De monogamia 10:5 [A.D. 216]).

Note that in this work Tertullian is excessively rigorous regarding matrimony, but the important thing for our purposes is that he is a witness to the fact that praying for the dead is unobjectionable, and the Christians believed that such prayers brought “refreshment” (refrigerium) to them.
Moving on to writers who are unquestionably Church Fathers, we have the following passage from Letter 51 of St. Cyprian of Carthage (who was, apparently, a pupil of Tertullian, although he rejected Tertullian’s rigorism and, evidently, never left communion with the Church). In his letter, St. Cyprian explains how it is possible for the Church to pardon apostates, adulterers, and others who have committed serious offences. It does not diminish the Church’s holiness, he argues, because she has re-admitted her lapsed sons; just as the Church is no less pure because some of her members have committed adultery and have been reconciled, neither is she less holy because she re-admits apostates and lapsi. In this context, he says,

It is one thing to stand for pardon, another thing to attain to glory: it is one thing, when cast into prison, not to go out thence until one has paid the uttermost farthing; another thing at once to receive the wages of faith and courage. It is one thing, tortured by long suffering for sins, to be cleansed and long purged by fire; another to have purged all sins by suffering. It is one thing, in fine, to be in suspense till the sentence of God at the day of judgment; another to be at once crowned by the Lord (Epistle 51[55]:20 [A.D. 253], emphasis added).

Here, St. Cyprian describes the doctrine that we are familiar with: it is possible for a person to expiate all of his sins in this life, and hence attain the crown of glory immediately upon his death; others, however, are purified after death.
Saint Cyril of Jerusalem, the bishop of Jerusalem from about 350–386, in one of his catecheses to catechumens, explains the suffrages to the dead in the liturgy:

Then we make mention [i.e., in the Canon or Eucharistic Prayer] also of those who have already fallen asleep: first, the patriarchs, prophets, apostles, and martyrs, that through their prayers and supplications God would receive our petition; next, we make mention also of the holy fathers and bishops who have already fallen asleep, and, to put it simply, of all among us who have already fallen asleep, for we believe that it will be of very great benefit to the souls of those for whom the petition is carried up, while this holy and most solemn sacrifice [i.e., the Divine Liturgy] is laid out (Catechetical Lectures 23:5:9 [A.D. 350], emphasis added).

In a sermon, Saint Gregory of Nyssa, one of the Cappadocian Fathers renowned for defending the divinity of the Holy Spirit and helping to formulate the Trinitarian dogmas in their present form, explains that those who have not led a life of virtue (especially, letting their passions dominate rather than reason), and yet is in friendship with God, will experience a purification after death:

If a man distinguish in himself what is peculiarly human from that which is irrational, and if he be on the watch for a life of greater urbanity for himself, in this present life he will purify himself of any evil contracted, overcoming the irrational by reason. If he has inclined to the irrational pressure of the passions, using for the passions the cooperating hide of things irrational, he may afterward in a quite different manner be very much interested in what is better, when, after his departure out of the body, he gains knowledge of the difference between virtue and vice and finds that he is not able to partake of divinity until he has been purged of the filthy contagion in his soul by the purifying fire (Sermon on the Dead [A.D. 382], emphasis added).

St. John Chrysostom, the renowned bishop and orator of Constantinople, in a homily on 1 Corinthians, teaches that offerings for the dead bring them consolation:

Let us help and commemorate them. If Job’s sons were purified by their father’s sacrifice [Job 1:5], why would we doubt that our offerings for the dead bring them some consolation? Let us not hesitate to help those who have died and to offer our prayers for them (Homilies on First Corinthians 41:5 [A.D. 392]).

Moreover, he explains in a homily of Philippians that there is the possibility of removing the residual effects of sin in this life. Nevertheless, for those who did not take advantage of that possibility, those still on earth can bring consolation to the deceased by offering prayers and giving alms:

Weep for those who die in their wealth and who with all their wealth prepared no consolation for their own souls, who had the power to wash away their sins and did not will to do it. Let us weep for them, let us assist them to the extent of our ability, let us think of some assistance for them, small as it may be, yet let us somehow assist them. But how, and in what way? By praying for them and by entreating others to pray for them, by constantly giving alms to the poor on their behalf. Not in vain was it decreed by the apostles that in the awesome mysteries [i.e., the Divine Liturgy, or celebration of the Eucharist] remembrance should be made of the departed. They knew that here there was much gain for them, much benefit. When the entire people stands with hands uplifted, a priestly assembly, and that awesome sacrificial Victim is laid out, how, when we are calling upon God, should we not succeed in their defense? But this is done for those who have departed in the faith, while even the catechumens are not reckoned as worthy of this consolation, but are deprived of every means of assistance except one. And what is that? We may give alms to the poor on their behalf (Homilies on Philippians 3:9–10 [A.D. 402], emphasis added).

It is interesting to note that St. John Chrysostom attributes the celebration of the mysteries (that is, of the Eucharist) for the sake of the departed to the authority of the apostles: this is evidence of an unwritten tradition that is recorded for the first time in Chrysostom’s day. (This one passage is not, of course, enough to prove the direct link to the Apostles, but the continuous existence of the belief and practice cannot be doubted.)
Finally, there are the works of St. Augustine, the bishop of the northern African town of Hippo from 395-430, the first Father to formulate the doctrine of Original Sin.
He explains in a sermon that prayers are not offered on behalf of the martyrs (because they presumably never needed to be purified after death); however prayers are offered for the sake of the other dead:

There is an ecclesiastical discipline, as the faithful know, when the names of the martyrs are read aloud in that place at the altar of God, where prayer is not offered for them. Prayer, however, is offered for other dead who are remembered. It is wrong to pray for a martyr, to whose prayers we ought ourselves be commended (Sermons 159:1 [A.D. 411]).

In a different sermon, explains that prayer and almsgiving on behalf of the dead bring them aid. He affirms that prayers and liturgical actions for the sake of the dead are a universal practice in the Church, and that the practice is already an old tradition (“from the Fathers”):

But by the prayers of the holy Church, and by the salvific sacrifice [i.e., the celebration of the Eucharist], and by the alms which are given for their spirits, there is no doubt that the dead are aided, that the Lord might deal more mercifully with them than their sins would deserve. The whole Church observes this practice which was handed down by the Fathers: that it prays for those who have died in the communion of the Body and Blood of Christ, when they are commemorated in their own place in the sacrifice itself; and the sacrifice is offered also in memory of them, on their behalf. If, then, works of mercy are celebrated for the sake of those who are being remembered, who would hesitate to recommend them, on whose behalf prayers to God are not offered in vain? It is not at all to be doubted that such prayers are of profit to the dead; but for such of them as lived before their death in a way that makes it possible for these things to be useful to them after death (Sermons 172:2, emphasis added).

He explains in his City of God that only those who have not been purified in this life must be purified in the next. He also affirms that not all punishment after death is eternal; there is a temporal punishment, or purification:

Temporal punishments are suffered by some in this life only, by some after death, by some both here and hereafter, but all of them before that last and strictest judgment. But not all who suffer temporal punishments after death will come to eternal punishments, which are to follow after that judgment (De civitate Dei 21:13 [A.D. 419]).

In what is probably the first use of the term purgatorium (“cleansing”)—and probably the source of the term Purgatory in the Middle Ages—Augustine affirms that some of the faithful are saved through a “cleansing fire.” (Augustine doubtless had in mind the passage from 1 Corinthians quoted above.)

That there should be some fire even after this life is not incredible, and it can be inquired into and either be discovered or left hidden whether some of the faithful may be saved, some more slowly and some more quickly in the greater or lesser degree in which they loved the good things that perish, through a certain purgatorial fire (per ignem quemdam purgatorium) (Handbook on Faith, Hope, and Charity 18:69 [A.D. 421]).

Note how St. Augustine uses fire in a strictly metaphorical sense, as do all the Fathers. A little later on, Augustine explains further, and as can be seen all the elements of the modern doctrine of Purgatory are in place: the fact the some persons die in friendship with God, but not perfectly purified (and that it is, is however, possible to be purified completely in this life); the possibility of purification after death; and the necessity to pray and make offerings for the dead, both personally and in the Liturgy (especially the celebration of the Eucharist, what Western Catholics call the Mass):

The time which interposes between the death of a man and the final resurrection holds souls in hidden retreats, accordingly as each is deserving of rest or of hardship, in view of what it merited when it was living in the flesh. Nor can it be denied that the souls of the dead find relief through the piety of their friends and relatives who are still alive, when the Sacrifice of the Mediator [i.e., the celebration of the Eucharist] is offered for them, or when alms are given in the Church. But these things are of profit to those who, when they were alive, merited that they might afterward be able to be helped by these things. There is a certain manner of living, neither so good that there is no need of these helps after death, nor yet so wicked that these helps are of no avail after death (Handbook on Faith, Hope, and Charity, 29:109).

If we add to this the witness of one of the last Western Fathers, St. Gregory the Great, quoted above in the text from the Catechism, it seems impossible to deny that belief in the doctrine of Purgatory has been present in the Church from the beginning, and in every part of the Church, both Eastern and Western. (It acquired the name “Purgatory” only in the Middle Ages, but the belief was there all the same.)
Conclusion
The Church would argue that there is a very strong argument for Purgatory from Tradition. The Scripture is not very explicit, but neither does it contradict the doctrine, and there are several important passages that support it: most notably 1 Corinthians 3:12-15. Although the Bible is not perfectly clear on this point, there is evidence of belief in a purification of the deceased after death among the Israelites at the time of the Maccabees, and of universal belief in Purgatory (though not, of course, by that name) among Christians from at least the second century A.D. The historical record shows that such a belief has been continuous to the present day, and that it was fundamentally uncontroversial until the late Middle Ages (when there began to be disputes with the Eastern Orthodox over the precise meaning of the term “Purgatory” and what sort of punishment it entailed).


The clue to understanding this is found in verse 12.

  1 Thessalonians 4:12 (NLT) Then people who are not Christians will
  respect the way you live, and you will not need to depend on others.

Living a quiet life: Paul instructed the Christians in Corinth to live peacefully and not fight among themselves. When the non-Christians see the peace among the Christians, they will be respected by the community. Christians should maintain good characters.
Work with your hands: Paul wanted them to be independent and prosperous so that they don't have to beg/ask from others. He encouraged them to work hard, make their own living without disturbing society. Paul did not want them to be lazy.


What spirit(s) is referred to in 1 John 4?

In verses 1–3, John speaks first of the "spirit of God VS the "spirit of antichrist".  In verses 4–6 he speaks of the "spirit of truth" VS the "spirit of falsehood" ("error" in KJV). These are the same two spirits; the restating of same concept in different terms is common in OT and NT. So the spirit of God is the spirit of truth, and the spirit of antichrist is the spirit of falsehood.  In other places, the devil/Lucifer is referred to as the father of lies:
John 8:44
      Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.

So yes, you could say that the devil (and his demons, if you believe in such) have the spirit of lies.


The word "ascended" and what does it mean "No one has ascended into heaven" in John 3:13?

I think for this question, the context is super important, here is verses 10-13 of john NKJV

  Jesus answered and said to him, “Are you the teacher of Israel, and do not know these things? 11 Most assuredly, I say to you, We speak what We know and testify what We have seen, and you do not receive Our witness. 12 If I have told you earthly things and you do not believe, how will you believe if I tell you heavenly things? 13 No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven.

The context here is talking about teaching. Nicodemus is "the teacher of Israel" i have heard this to imply that he was quite possibly THE teacher in Israel, maybe there was no one above him. He was supposed to be the guy with all the answers.

But still he had doubts and questions, which is why he came to Jesus by night.

So in the context, when Jesus is saying "No one has ascended to heaven" he is referencing teaching, how he (Jesus) is not guessing, or passing along secondhand information, Jesus says

  13a "Most assuredly, I say to you, We speak what We know and testify what We have seen, "

The Emphasis is that no one on earth is is able to teach the things Jesus can teach, Because no one has "Ascended" to heaven, for the purpose of returning and teaching the truths of heaven, on earth.

I believe jesus is less making a blanket statement about whether anyone has gone to heaven to that date, and making a strong point about his unique ability to teach the truths of God which he knows by personal experience, because he is come down from heaven, something no one else has ever done.

So i think to sum it all up for an answer to your question, the best understanding of the sentence

  No one has ascended into heaven except he who descended from heaven, the Son of Man

C. No living human person has gone up to heaven to learn these things and returned to teach them, Except for Jesus, who came Down from heaven already knowing them.