Would you sell your soul to the devil?

Any deals to sell your soul is contingent upon getting you to maintain that "no way out" illusion until you die, at which point there really is no way out. It can be a harder road for those active in the occult etc, than for the average person, but Grace qualifies for them as well. The way I've heard it described for these guys, who will repent and give their hearts to Jesus, but will still find demonic chicanery at work against them, was aptly compared to the Apostle Peter's denial of Jesus during the Crucifixion. He denied Him three times, after which, Jesus appeared to him three times and asked him if he loved Him. So I believe this is more for the benefit of the human than anything else, to prove their love for Him.

So when someone who has "sold their soul" is called to Jesus, they may have some dark fights, burn that inner light is still burning, "You know I love you, Lord!"

The demons are fighting a war of retreat and attrition, they're bitter and any little battle they can win they will sneer and jeer over. They're also not omniscient and have no idea when the fight is futile and when the fight may actually be won by them.

In closing, don't forget, some demons only come out by prayer AND fasting.