I disagree. Demons were ancient man’s attempt to explain things that people did that they did not understand. Mental illness, brain damage were things ancient man did not comprehend. So they invented demons to “explain” these occurrences in people. And thru history whenever people wanted to either frighten or ostracize someone they called them demons or claimed they were demonically possessed.
If demons are real why have we not captured any photographs of one?? Oh wait...they are conveniently invisible.
Take a picture of the wind
I guess that makes you a gravity denier. I've never seen gravity, only it's effects, and that's enough to convince me at exists.