God sends them a powerful delusion so… they will believe the lie.” 2 Thessalonians 2:11
This is “the lie,” and it goes all the way back to the Garden of Eden when Satan said, “You will be like God” (Genesis 3:5). You’re a good person. You don’t need Christ’s sacrifice. You can work it out yourself.
When a man feels that he is the captain and commander of his own life, that he is his own god, his own law and that he can stand on his own goodness, you know that he has swallowed the lie, and he is living under a powerful delusion.