Is there a spirit world? I think you could ask a thousand people at random, and by far the majority would say yes, there is a spirit world. But when you start asking for details about that world, you will find a lot of opinion, a lot of unprovable stories, and very little hard data. And most people seem to be afraid of the spirit world. They don’t think of it in terms of religion, but of demons, ghosts, and the presence of great evil. The presence of evil in the world is a fact. but the origin of that evil is not at all clear.
There is a spirit world. It is like another dimension, parallel to our own. There are times and circumstances that seem to allow interaction between these worlds, but that interaction is not unlimited or at will. For the most part, humans cannot access that world, and the inhabitants of that world cannot routinely access the physical world.
There is an incredible amount of mythology surrounding it, much of it entirely untrue, much of it may be generated by Lucifer himself. Misdirection has always been a powerful tool. A lot of misunderstanding comes from the misapprehension of the word “evil.” As used in the Bible, it means adverse, adversity, opposition. There is wickedness in the world that is NOT spiritual, but human evil. It is tempting to blame all evil in the world on Satan, but that does not seem to be the case.