The Apostle John in his First Letter, chapter 2, verses 18-23, is dealing with the threats of heresies that are already rearing their heads in the earliest days of the Church. He is plain in his language calling them "antichrists." These are people who "went out from us, but they were not really of our number; if they had been, they would have remained with us" (verse 19). John is counseling us as to how to recognize these antichrists. They will be known by their lies. They will reveal themselves as aliens to the truth.
"Who is the liar then? Whoever denies that Jesus is the Christ." (verse 22) There were already those in the early Christian communities who were doing this. They were gnostics and Arians and Manicheans, who claimed to be Christians but denied the divinity of Christ, saying that he was a man only, a special man, and a prophet, but not the Son of God. They claimed to have a special knowledge from God that only a chosen few could know. Their lies could often be very subtle. This is why John felt it necessary to remind the faithful, to be wary of their subtle lies and arguments and how they diverged from the true teachings of Jesus. The lie, in the end, is a denial of reality. It is the instrument of manipulation. It is that which sows division and causes doubt. It is full of guile. It is used to lead others astray. It is the tool of oppression and the source of misery. It is the destroyer of trust. There is no life in the lie. The lie is the tool of the Fallen One, Satan, the Prince of Lies.
Jesus Christ is the Prince of Peace, the source of all that is good, true, and beautiful. There is no guile in him. In him we find only love and mercy. He is the Self-Giving One. He did not even claim his own life as his own, but spent it all, obedient to his Father, in order to reconcile us to the Father, and to conquer sin and death forever. Jesus is the Risen One, the only begotten Son of the Father, the One who has come to draw us all together as one. "Whoever denies the Father and the Son, this is the antichrist. No one who denies the Son has the Father, but whoever confesses the Son has the Father as well." (verses 22&23) Why? Because the Father and the Son are One in the Holy Spirit. One can also say that one who denies the Holy Spirit, denies the Father and the Son. Such a one is a liar.
Lord, give us the wisdom to recognize your truth and the courage to remain faithful to it in this world that is so often tortured by lies. Give us an ever-deepening desire to meditate on the scriptures, and to pray always with sincere, contrite, and humble hearts. Draw us nearer to you each and every day. Protect us from the lie and those who spread it. We pray in your name, Jesus. Amen!