John Chrysostom

"For because they received not the love of the truth, that they might be saved; for this cause God will send them a working of error, that they should believe a lie: that they all might be judged who believed not the truth, but had pleasure in unrighteousness." "That they might be judged." He does not say, that they might be punished; for even before this they were about to be punished; but "that they might be condemned," that is, at the dreadful Seat of Judgment, in order that they might be without excuse. …

Homily on 2 Thessalonians 4 ↗

Theophylact of Ohrid

He will be fearsome everywhere by his power, because he will do everything with cruelty, in order to seduce people and cause them harm, destroying their salvation. But lest anyone become perplexed, saying: why did God allow him to come, when people must suffer so much harm? the apostle answers: do not fear! He will prevail over those who are perishing, who, even if he had not come, would have remained unbelievers. …

Commentary on 2 Thessalonians ↗

Cyprian

Finally, their mind is smitten by these things, and their spirit is dull, and their sense of right is estranged: it is God's wrath that they do not perceive their sins, lest repentance should follow as it is written, "And God gave them the spirit of torpor," that is, that they may not return and be healed, and be made whole after their sins by just prayers and satisfactions. Paul the apostle in his epistle lays it down, and says, "They received not the love of the truth, that they might be saved. …

Epistle LIV ↗

Thomas Aquinas

Then he sets out those who will be deceived, when he says "to those who perish", i.e., among those who God foreknows will perish. "None of them was lost save the son of perdition" (John 17:12). And this is because "my sheep hear my voice" (John 10:27). Having described those in whom the Antichrist has power to deceive, namely those foreknown as going to suffer damnation, here the Apostle gives the reason for what he has said. …

Commentary on 2 Thessalonians ↗

Victorinus of Pettau

"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. …

Victorinus Commentary on the Apocalypse of the Blessed John ↗