The idea of a mighty ruler who will appear at the end of time to fight against the forces of good was adapted from Judaism; the Jewish concept in turn had been influenced by Iranian and Babylonian myths of the battle of God and the devil at the end of time.

The Antichrist will pose as the Messiah and will perform things wonderful enough to mislead the elect themselves. The thunder will obey him, according to St. John, and Leloyer asserts that the demons below watch over hidden treasures with which he will be able to tempt many. Because of the miracles that he will perform, Boguet calls him the "Ape of God," and it is through this scourge that God will proclaim the final judgment.

Antichrist will have a great number of forerunners and will appear just before the end of the world. St. Jerome claimed that he will be a man fathered by a demon; others said that he will be a demon in the flesh. But, following the thinking of Saints Ireneus, Ambrose, Augustine and almost all of the church fathers, Antichrist will be a man similar to and conceived in the same way as all others, differing from them only in a malice and an impiety more worthy of a demon than of a man. More recently, however, Cardinal Bellarmin asserted that Antichrist will be the son of a demon incubus and a sorceress.