The Church's ultimate trial

675 Before Christ's second coming the Church must pass through a final trial that will shake the faith of many believers.574 The persecution that accompanies her pilgrimage on earth575 will unveil the "mystery of iniquity" in the form of a religious deception offering men an apparent solution to their problems at the price of apostasy from the truth. 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.
676 The Antichrist's deception already begins to take shape in the world every time the claim is made to realize within history that messianic hope which can only be realized beyond history through the eschatological judgment. The Church has rejected even modified forms of this falsification of the kingdom to come under the name of millenarianism, [DS 3839] especially the "intrinsically perverse" political form of a secular messianism. (Pius XI, Divini Redemptoris, condemning the "false mysticism" of this "counterfeit of the redemption of the lowly"; cf. GS 20-21.)