"Their minds were blinded ... the veil is upon their heart."
God blinds people to prevent them from seeing the truth. 3:15-16

The god of this world (Satan) has blinded the eyes of non-believers (lost people), who will be sent to hell by God after they die. 4:3-4

Jesus, who was without sin, was made into sin. This made the real sinners sinless. 5:21

Keep away from unbelievers. Neither marry nor be friends with them. 6:14-17

Paul set an example for televangelists by robbing some churches. 11:8

"Being crafty, I [Paul] caught you with guile." 12:16

Paul says he "will not spare" when he comes back to punish those who have sinned. 13:2

Are you a reprobate? Here's the test: if you know for sure that Jesus is in you, you're not a reprobate. Otherwise you are. 13:5