There is this question that comes really often during the course of my other discussion and it is beginning to seriously impede the evolution of the discussion.
So does God exists as a separate entity - separate from human brains? Yes
How can you prove it?
The same way you prove the existence of something immaterial as a separate entity - separate from human brains. Through it's definition.
Or using the ontological argument.
When we look at a real thing, reports of it tend to narrow towards a single story as the picture gets clearer. Is that what happens when we examine reports about gods?
No. When we examine reports about gods, the stories tend to diverge to the point where just about every believer has their own personal version different from all the others.
Where else do we see this same divergence effect? In the examination of subjective phenomenon where people are free to make up anything they like.