I have seen the idea of demonic possession in action: My brother is a crackhead and when seeking the drug is inhabited by a cunning demonic spirit.
He has admitted that he is weak and that the spirit seeking pleasure uses him to experience the drug.
It is spooky when he is in the grip of that energy.
I caught my brother in law going threw my purse for money to get his very needed fix. When I ripped my purse from his hands and asked him why he thought I should pay for his weakness( yes, I know those were not smart words to say to a man in his condition)he picked me up and threw me down the 6 concrete steps to my own house.