its called de-ja-vu (cant spell), in dream form i have had almost incapacitating bouts of it, I know how disturbing that feeling can be. but after a little research... it is to do with how the brain processes its experiences of the world and how memory works.
contrary to popular belief the role of the hippocampus (the bit of the brain that deals with memory)
is not to remember stuff, but to decide which stuff to forget. every day everything you see, smell, hear etc. is stored even if your concious mind is unaware of it. the process of your hippocampus sorting through what to keep and what to ditch is your dreams. however a little like deleting stuff from your hard drive things in your memory don't get removed completely right away "just in case". but the storage of this residual information is not as accurate, so when combined with things happening at the time it can seem like you have dreamt an experience or been to a place you have never heard of. this is the result of new memories merging with the old ones that have not been fully "deleted"
if you are interested I recommend reading up on it, my explanation is very basic and many professionals would say I have explained it badly but its late i've been drinking and didn't fancy writing a dissertation on a forum
I wont comment on organised religion it'd probably get me banned, everyone is entitled to their own beliefs.
more people should read the bible though, there's no quicker way to become an atheist than reading it cover to cover.