I went to a Catholic school for 8 FUCKING YEARS. I know what you mean. I told almost everyone I was an Atheist and almost all of them thought I was a retard immediately. They really don't get it. I've gone to school with them for 6 years, and they think I'm an asshole just because I'm an Atheist. I had been an Atheist for about 5 years, and that didn't stop me from being friends with most of them. Some didn't care - these people I'm still friends with - others TRIED to make fun of me. They tried, but I just turned it back onto the Catholic faith and shut down all Religion conversation of the rest of forever. People need to learn this: There are 2 types of Atheists - douche bags, and regular people. I don't need to explain the former, but people's stereotype about Atheism is so far from the truth it hurts.
I could keep droning on, but I'll spare all of you from that.