Yom Kippur's principal theme is atonement. Our deeds are recorded on Rosh Hashanah in the Heavenly Court; on Yom Kippur the "Books of Judgment" are sealed. The Day of Atonement combines the elements of remorse and confession with those of prayer and spiritual purification." To enhance this process, we fast in accordance with the biblical command "you shall afflict your souls" (Lev. 23:23-32).
Yom Kippur is also a Holiday (Yom Tov). According to tradition, Yom Kippur is the day on which Moses descended from Mt. Sinai with the second Tablets of Stone, forty days after the collective sin of the Golden Calf. This time he was greeted with joy.
High Priest In Temple times the people celebrated the successful emergence of the High Priest from the holy sanctuary after he had atoned for the entire community. There was singing and dancing. With the emerging innocence, as Yom Kippur day progressed, it was also customary for potential grooms to choose their future brides.
In honor of the holiday (Yom Tov) it is customary to wear best clothes and to prepare the house as we would for Shabbat and other festivals.
Before the Fast: Erev Yom Kippur
Yom Kippur marks the climax of the Ten Days of Repentance (Aseret Yemei Teshuvah). As such the day preceding Yom Kippur is replete with anticipation and special custom:
Festive meals. The eve of Yom Kippur is characterized by a solemn yet optimistic mood. It is a mitzvah to eat well before Yom Kippur. Some say that this reflects the joy and relief that the upcoming atonement will offer. Others suggest that, besides providing strength for the fast, a generous meal on the afternoon before Yom Kippur replaces the missing festive meal that accompanies Jewish holidays.
It is customary not to partake of fish or intoxicating drinks at this meal. Charity. Since, according to tradition, the merit of charity shields against an unfavorable decree, it is customary to give in a liberal spirit before Yom Kippur.
Immersion in a Mikveh (Ritual Bath). Many pious Jews immerse themselves in a ritual bath before the Day of Atonement in order to enter into the penitent spirit in as "pure" a manner as possible.
Honoring the Festival. We honor the festival with festive clothing and a Shabbat atmosphere in the house. The candles are lit with two blessings: "...lehadlik ner shel Shabbat veYom HaKippurim" and "...shehecheyanu vekiymanu vehigianu lazman hazeh" which respectively usher in the Shabbat (this year) and festival, and express our gratitude to God for our living to enjoy this auspicious occasion.
Yahrzeit Candles. Many also light Yahrzeit candles for the departed, for: "The soul of man is the candle of God." Asking Forgiveness from Others. Yom Kippur atones only for sins between man and God. It is essential for sins between man and his fellow "to be righted." It is thus meritorious to ask for forgiveness from those one might have wronged, and to forgive others in a liberal spirit.
Prohibitions The concept of "You shall afflict your soul..." has been interpreted as spiritual suffering. The rabbis listed five prohibitions falling within this domain:
Work Eating and drinking Washing and anointing with creams, lotions, etc. Wearing leather or leather covered shoes Intimacy Pikuach nefesh: Danger to life (even doubtful) overrides all prohibitions of Yom Kippur.
Prayers The major themes of the day are repentance and forgiveness.
There are five services during Yom Kippur. In addition to Selichot(penitential prayers) and Piyutim (liturgical poems) throughout the special prayer book, the Machzor, main highlights include: Kol Nidrei: The evening service is preceded by the chanting of Kol Nidrei (lit. 'All the Vows'). This is a formal abrogation of all vows made during the past year. Before embarking on a day of prayer, Kol Nidrei stresses the importance of the words emanating from our mouths. It is an impassioned plea to God to annul "vows' taken in innocence, or otherwise.
Confession (Vidui): The ritual of Yom Kippur is replete with petitions for the forgiveness for sins. These are listed as a series of misdeeds and are recited by both the individual and the community. The sins are listed in the plural implying that Jews are responsible for one another. As each of the wrong-doings is recited, members of the congregation beat their hearts to emphasize the more "subjective" side of the sin.
Avodah: "Recalling the Temple Service." This is part of the additional service (Mussaf) and is a record of the impressive ritual of Temple days when the High Priest alone entered the Holy of Holies on Yom Kippur. The descriptions of this elaborate ceremony and of the subsequent exaltation of the people offer a rare insight into the poignant spirit of the day. At certain points in this recitation, the congregation prostrate themselves in total submission to God.
Jonah: The Book of Jonah: The Book of Jonah is read during the Minchah (afternoon) service on Yom Kippur. It tells the story of the prophet Jonah who lived c. 750 BCE.
Jonah attempted to escape the divine command to prophesy about the destruction of the evil people of Nineveh by sailing from the Land of Israel. During a storm, Jonah is thrown overboard, delivered miraculously from a whale, and commanded to continue his mission. God spared the city when he saw the repentance of its people.
Among other lessons, the story demonstrates the power of atonement and how God's compassion extends to all His creatures.
Ne'ilah: The afternoon service is followed by Ne'ilah (lit. Closure). This is a collection of prayers which are invested with special significance as the Gates of Heaven symbolically close and an air of relief and optimism descends upon the weary worshippers who have been outpouring their souls throughout the day.
The service and the fast conclude with the blast of the shofar, a call for the unity of all Jews in the holy city of Jerusalem, and a proclamation of God's kingship over Israel in the famous call: "Shema Yisra'el Hashem Elokeinu Hashem Echad"!
On returning home, the Havdalah ceremony is recited for Yom Kippur.