Albert Barnes Commentary 2 Thessalonians 2:11

"And for this cause God sendeth them a working of error, that they should believe a lie:" — 2 Thessalonians 2:11 (ASV)

And for this cause. Because they chose error, or their hearts love that more than they love truth. The original reason, then, for 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 demonstrate 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 recognized, in accordance with the uniform statements of the Scriptures, respecting evil (9:12; 10:1, 20, 27; 11:10; 14:8; Deuteronomy 2:30; Isaiah 45:7). On the nature of this agency, see Barnes 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 allowed men simply to show that they did not love the truth. God often places men in circumstances to develop their own nature, and it cannot be shown to be wrong that he should do so. If men 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 pertain. (Compare to Romans 9:17, Romans 9:18; and Romans 1:24. See Barnes' commentary on these passages.)

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? Men are left to believe impostors; to trust 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 use direct power to preserve them.

Can anyone doubt this? Yet this is not uniquely the doctrine of revelation. The fact pertains just as much to the unbeliever 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 uniquely pertaining to that system.