When discussing the end times, the topic of the Antichrist will inevitably come up, as he is specifically mentioned throughout the New Testament.
Specifically, the Antichrist is mentioned in the letters of St. John:
Children, it is the last hour; and as you have heard that antichrist is coming, so now many antichrists have come; therefore we know that it is the last hour.
Jesus did not mention that exact phrase, but he did refer to false messiahs:
“Take heed that no one leads you astray. For many will come in my name, saying, ‘I am the Christ,’ and they will lead many astray."
Some have thought that the words of the Bible are referring to a political movement or a world power, or even the Papacy, but according to St. John Henry Newman, the Church Fathers affirmed that it will be a man:
[T]hat Antichrist is one individual man, not a power,—not a mere ethical spirit, or a political system, not a dynasty, or succession of rulers,—was the universal tradition of the early Church. "We must say," writes St. Jerome upon Daniel, "what has been handed down to us by all ecclesiastical writers, that, in the end of the world, when the Roman Empire is to be destroyed, there will be ten kings, to divide the Roman territory between them, and that an eleventh will rise up, a small king, who will subdue three of the ten, and thereupon receive the submission of the other seven. It is said that 'the Horn had eyes, as the eyes of a man,' lest we should, as some have thought, suppose him to be the evil spirit, or a demon, whereas he is one man, in whom Satan shall dwell bodily. 'And a mouth speaking great things;' for he is the man of sin, the son of perdition, so that he dares to 'sit in the Temple of God, making himself as if God.'"
Man of sin
St. Paul speaks about this "man of sin" in his letter to the Thessalonians:
That you be not easily moved from your sense, nor be terrified, neither by spirit, nor by word, nor by epistle, as sent from us, as if the day of the Lord were at hand.
Let no man deceive you by any means, for unless there come a revolt first, and the man of sin be revealed, the son of perdition,
Who opposeth, and is lifted up above all that is called God, or that is worshipped, so that he sitteth in the temple of God, shewing himself as if he were God.
The Catholic Encyclopedia explains: "The Pauline doctrine is this: 'the day of the Lord' will be preceded by 'a revolt,' and the revelation of the 'man of sin.' The latter will sit in the temple of God, showing himself as if he were God; he will work signs and lying wonders by the power of Satan; he will seduce those who received not the love of the truth, that they might be saved; but the Lord Jesus shall kill him with the spirit of His mouth, and destroy him with the brightness of His coming."
The Catechism of the Catholic Church affirms the teaching of a particular Antichrist, though does not give many details and opens the door to multiple possibilities:
The supreme religious deception is that of the Antichrist, a pseudo-messianism by which man glorifies himself in place of God and of his Messiah come in the flesh.
So far no one has been successfully identified as the Antichrist, though many have acted "in his spirit."
The spirit of the Antichrist is alive "every time the claim is made to realize within history that messianic hope which can only be realized beyond history through the eschatological judgment" (CCC 676).
