2:5-12 Something hindered or withheld the man of sin. It is supposed to be the power of the Roman empire, which the apostle did not mention more plainly at that time. Corruption of doctrine and worship came in by degrees, and the usurping of power was gradual; thus the mystery of iniquity prevailed. Superstition and idolatry were advanced by pretended devotion, and bigotry and persecution were promoted by pretended zeal for God and his glory. This mystery of iniquity was even then begun; while the apostles were yet living, persons pretended zeal for Christ, but really opposed him. The fall or ruin of the antichristian state is declared. The pure word of God, with the Spirit of God, will discover this mystery of iniquity, and in due time it shall be destroyed by the brightness of Christ's coming. Signs and wonders, visions and miracles, are pretended; but they are false signs to support false doctrines; and lying wonders, or only pretended miracles, to cheat the people; and the diabolical deceits with which the antichristian state has been supported, are notorious. The persons are described, who are his willing subjects. Their sin is this; They did not love the truth, and therefore did not believe it; and they were pleased with false notions. God leaves them to themselves, then sin will follow of course, and spiritual judgments here, and eternal punishments hereafter. These prophecies have, in a great measure, come to pass, and confirm the truth of the Scriptures. This passage exactly agrees with the system of popery, as it prevails in the Romish church, and under the Romish popes. But though the son of perdition has been revealed, though he has opposed and exalted himself above all that is called God, or that is worshipped; and has spoken and acted as if he were a god upon earth, and has proclaimed his insolent pride, and supported his delusions, by lying miracles and all kinds of frauds; still the Lord has not yet fully destroyed him with the brightness of his coming; that and other prophecies remain to be fulfilled before the end shall come.

11. for this cause—because "they received not the love of the truth." The best safeguard against error is "the love of the truth."

shall send—Greek, "sends," or "is sending"; the "delusion" is already beginning. God judicially sends hardness of heart on those who have rejected the truth, and gives them up in righteous judgment to Satan's delusions (Isa 6:9, 10; Ro 1:24-26, 28). They first cast off the love of the truth, then God gives them up to Satan's delusions, then they settle down into "believing the lie": an awful climax (1Ki 22:22, 23; Eze 14:9; Job 12:16; Mt 24:5, 11; 1Ti 4:1).

strong delusion—Greek, "the powerful working of error," answering to the energizing "working of Satan" (2Th 2:9); the same expression as is applied to the Holy Ghost's operation in believers: "powerful" or "effectual (energizing) working" (Eph 1:19).

believe a lie—rather, "the lie" which Antichrist tells them, appealing to his miracles as proofs of it … (2Th 2:9).