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.