I've seen so much weirdness but I have no idea if I'd call it dead people. Like I had an invisible cat that sometimes slept in my bed. Who am I to judge it was dead? It might just have been a cat from another dimension, and maybe I look like a ghost in theirs.

Anyway I will make no judgment about beliefs, I used to know a bunch of Satanists that were the nicest people you could meet. Everyone is entitled to their belief system.