The working of delusion. He means that errors will not merely have a place, but the wicked will be blinded, so that they will rush forward to ruin without consideration. For as God enlightens us inwardly by his Spirit, that his doctrine may be efficacious in us, and opens our eyes and hearts, that it may make its way thither, so by a righteous judgment he delivers over to a reprobate mind (Romans 1:28) those whom he has appointed to destruction, that with closed eyes and a senseless mind, they may, as if bewitched, deliver themselves over to Satan and his ministers to be deceived. And assuredly we have a notable specimen of this in the Papacy. No words can express how monstrous a sink of errors [1] there is there, how gross and shameful an absurdity of superstitions there is, and what delusions at variance with common sense. None that have even a moderate taste of sound doctrine, can think of such monstrous things without the greatest horror. How, then, could the whole world be lost in astonishment at them, were it not that men have been struck with blindness by the Lord, and converted, as it were, into stumps?

Footnotes

1 - "Quel monstrueux et horrible retrait d'erreurs;" -- "What a monstrous and horrible nest of errors."

And for this cause - Because they choose error, or their hearts love that more than they do truth. The original reason then of their embracing and adhering to the system was not an arbitrary decree on the part of God, but that they did not love the truth. Hence, he gave them up to this system of error. If a man strongly prefers error to truth, and sin to holiness, it is not wrong to allow him freely to evince his own preference.
God shall send them strong delusion - Greek: "energy of deceit;" a Hebraism, meaning strong deceit, The agency of God is here distinctly recognised, in accordance with the uniform statements of the Scriptures, respecting evil; compare Exodus 7:13; Exodus 9:12; Exodus 10:1, Exodus 10:20, Exodus 10:27; Exodus 11:10; Exodus 14:8. Isaiah 45:7. On the nature of this agency, see the notes on John 12:40. It is not necessary here to suppose that there was any positive influence on the part of God in causing this delusion to come upon them, but all the force of the language will be met, as well as the reasoning of the apostle, by supposing that God withdrew all restraint, and suffered men simply to show that they did not love the truth. God often places people in circumstances to develop their own nature, and it cannot be shown to be wrong that He should do so. If people have no love of the truth, and no desire to be saved, it is not improper that they should be allowed to manifest this. How it happened that they had no "love of the truth," is a different question, to which the remarks of the apostle do not appertain; compare Romans 9:17-18, note; Romans 1:24, note.
That they should believe a lie - This does not affirm that God wished them to believe a lie; nor that He would not have preferred that they should believe the truth; nor that He exerted any direct agency to cause them to believe a lie. It means merely that He left them, because they did not love the truth, to believe what was false, and what would end in their destruction. Can anyone doubt that this constantly occurs in the world? People are left to believe impostors; to trust to false guides; to rely on unfounded information; to credit those who live to delude and betray the innocent; and to follow those who lead them to ruin. God does not interpose by direct power to preserve them. Can anyone doubt this? Yet this is not especially the doctrine of revelation. The fact pertains just as much to the infidel as it does to the believer in Christianity, and he is just as much bound to explain it as the Christian is. It belongs to our world - to us all - and it should not be charged on Christianity as a doctrine pertaining especially to that system.

God shall send them strong delusion - For this very cause, that they would not receive the love of the truth, but had pleasure in unrighteousness, therefore God permits strong delusion to occupy their minds; so that they believe a lie rather than the truth, prefer false apostles and their erroneous doctrines to the pure truths of the Gospel, brought to them by the well-accredited messengers of God; being ever ready to receive any false Messiah, while they systematically and virulently reject the true one.

And for this cause God shall send them (n) strong delusion, that they should believe a lie:
(n) A most mighty working to deceive them.

And for this cause God shall send them strong delusion,.... Or "efficacy of error", which God may be said to send; and the Alexandrian copy reads, "does send"; because it is not a bare permission but a voluntary one; or it is his will that error should be that truth may be tried, and be illustrated by its contrary, and shine the more through the force of opposition to it; and that those which are on the side of it might be made manifest, as well as that the rejecters of the Gospel might be punished; for the efficacy of error is not to be considered as a sin, of which God cannot be the author, but as a punishment for sin, and to which men are given up, and fall under the power of, because they receive not the love of the truth, which is the reason here given: and this comes to pass partly through God's denying his grace, or withholding that light and knowledge, by which error may be discovered and detected; and by taking from men the knowledge and conscience of things they had, see Romans 1:28. So that they call evil good, and good evil, and do not appear to have the common sense and reason of mankind, at least do not act according to it; and by giving them up to judicial blindness and hardness of heart, and to the god of this world, to blind their minds; and without this it is not to be accounted for, that the followers of antichrist should give into such senseless notions as those of transubstantiation, works of supererogation, &c., or into such stupid practices as worshipping of images, praying to saints departed, and paying such a respect to the pretended relics of saints, &c., as they do; but a spirit of slumber is given them, and eyes that they should not see, and ears that they should not hear, because of their rejection of the Gospel: and
that they should believe a lie; that the pope is Christ's vicar on earth, and has power to forgive sins; that the bread and wine in the Lord's supper are transubstantiated into the very body and blood of Christ; with other lying tenets spoken in hypocrisy concerning good works, merit, pardon, penance; &c. with a multitude of lying wonders and false miracles, of which their legends are full; and this is the first and more near end of strong delusion or efficacious error being sent them; the more remote and ultimate one follows.

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 (Isaiah 6:9-10; Romans 1:24-26, Romans 1:28). 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 (1-Kings 22:22-23; Ezekiel 14:9; Job 12:16; Matthew 24:5, Matthew 24:11; 1-Timothy 4:1).
strong delusion--Greek, "the powerful working of error," answering to the energizing "working of Satan" (2-Thessalonians 2:9); the same expression as is applied to the Holy Ghost's operation in believers: "powerful" or "effectual (energizing) working" (Ephesians 1:19).
believe a lie--rather, "the lie" which Antichrist tells them, appealing to his miracles as proofs of it . . . (2-Thessalonians 2:9).

For this cause God shall send them strong delusion. Because they do not receive the truth. He who refuses to receive the truth will at last believe lies. It is the law of human nature. God sends the delusion by natural laws.
Be damned. Because "they had pleasure in unrighteousness."

Therefore God shall send them - That is, judicially permit to come upon them, strong delusion.