As an American, I honestly haven't run into this. I am religious, and most of my coworkers are religious, but we have had an atheist and an agnostic in our group (we're all developers) and it really didn't seem to matter. Religion rarely comes up in a professional setting, and it didn't come up when we did things outside of work as friends.
As long as you aren't aggressive against that which you don't believe, there really shouldn't be any problems. Most of the problems I run into are from atheists and agnostics picking a fight with theists. Treat others with respect and you'll get it in return.