I myself have trouble believing in that demon shyt since I have never experience something even close to it.
Couple of things I can add to this thread though.
I had an art teacher in high school who was well versed in that spiritual stuff. He was apparently very familiar with OBE and gave us this example once :
Basically his girlfriend at the time did not believe in that stuff at all so in order to demonstrate the out of body experience, he had her write some note on a piece of paper that she would put on the top shelf of a drawer, out of his reach. Apparently this OBE thing was a second nature and so he could pull it off at will. So dude basically laid on the bed with his gf in the room and floated outside of his body so that we could read the note on the shelf, "wake up" and tell his gf what was written.
Another thing is simply experiences from me travelling the world and living with locals from different cultures. Wherever I went, it was extremely interesting to find out that all these different cultures shared unusually similar ghost & spirit stories. Whatever I would say, there was no rationalization that could shake their profound belief in those entities. It was truly disturbing to see the fear in their eyes when speaking of them