2 Thessalonians 2:7

For the mystery of iniquity is already at work, only that he who now holds back may hold back until he is taken out of the way. The mystery of iniquity began with Nero, who, encouraged by his father the devil, killed the apostles with a zeal for idols, up until Diocletian and finally Julian, who, with a certain art and cunning, could not complete the started persecution because it had not been allowed from above. Satan uses these ministers to deceive men under the guise of a multitude of gods, as long as the Roman kingdom, that is what he says: Until he is taken out of the way.

But others think that the words, "Ye know what withholdeth," and "The mystery of iniquity worketh," refer only to the wicked and the hypocrites who are in the Church, until they reach a number so great as to furnish Antichrist with a great people, and that this is the mystery of iniquity, because it seems hidden; also that the apostle is exhorting the faithful tenaciously to hold the faith they hold when he says, "Only he who now holdeth, let him hold until he be taken out of the way," that is, until the mystery of iniquity which now is hidden departs from the Church. For they suppose that it is to this same mystery John alludes when in his epistle he says, "Little children, it is the last time: and as ye have heard that Antichrist shall come, even now are there many antichrists; whereby we know that it is the last time. They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us." As therefore there went out from the Church many heretics, whom John calls "many antichrists," at that time prior to the end, and which John calls "the last time," so in the end they shall go out who do not belong to Christ, but to that last Antichrist, and then he shall be revealed.

"And the beast which ascendeth from the abyss." After many plagues completed in the world, in the end he says that a beast ascended from the abyss. Bat that he shall ascend from the abyss is proved by many testimonies; for he says in the thirty-first chapter of Ezekiel: "Behold, Assur was a cypress in Mount Lebanon." Assur, deeply rooted, was a lofty and branching cypress-that is, a numerous people-in Mount Lebanon, in the kingdom of kingdoms, that is, of the Romans. Moreover, that he says he was beautiful in offshoots, he says he was strong in armies. The water, he says, shall nourish him, that is, the many thousands of men which were subjected to him; and the abyss increased him, that is, belched him forth. For even Isaiah speaks almost in the same words; moreover, that he was in the kingdom of the Romans, and that he was among the Caesars. The Apostle Paul also bears witness, for he says to the Thessalonians: "Let him who now restraineth restrain, until he be taken out of the way; and then shall appear that Wicked One, even he whose coining is after the working of Satan, with signs and lying wonders." And that they might know that he should come who then was the prince, he added: "He already endeavours after the secret of mischief" -that is, the mischief which he is about to do he strives to do secretly; but he is not raised up by his own power, nor by that of his father, but by command of God, of which thing Paul says in the same passage: "For this cause, because they have not received the love of God, He will send upon them a spirit of error, that they all may be persuaded of a lie, who have not been persuaded of the truth." And Isaiah saith: "While they waited for the light, darkness arose upon them." Therefore the Apocalypse sets forth that these prophets are killed by the same, and on the fourth day rise again, that none might be found equal to God.