I'm actually in a very similar situation, and I have not yet figured out what to do about it. I think it boils down to how much you're willing to hurt your friends and family (make no mistake, it will hurt them) in exchange for being public with your true thoughts. Not that it is easy to keep it to yourself when people around you are going on about some superstition, but, I have found no way to extricate myself from the world I live in.
I wonder if this is due to this being an impossible (extremely difficult) situation to extricate yourself from cleanly? I would find this very sad, as I love my friends and family deeply, and on some level would like to share my thoughts with them. I won't do so if it will cause them harm or push them away.