Book Reqs Please!

Hey guys!  I'm wondering if anyone knows of any books that explain why we have religion, with the answer being aliens?

This is kind of hard to explain.  I'm looking for something FICTIONAL.  Something where, the answer to why we have religion in our world is because we have confused aliens, with angels/demons.

Does this make sense?

My mom says there are a lot of books that do that, but couldn't name any.

Thanks guys!
Sorry for the ambiguity.