It shouldn't unless you are in a religious school or something. I'm an atheist and i don't even think about religion in my daily life and haven't thought about it for years, I even went to church for a few years with my Catholic girlfriend and didn't have a problem. If you treat other religious people with respect it shouldn't be a problem, there is no need for trying to show them that God doesn't exist, they won't change their mind. Religion is history and mythology, it can be cool to learn about if you view it though the lens of myths and legends instead of fact. I like to learn about the stories of the Volsung, the Monkey King, Dietrich of Bern, Achilles and Odysseus. Religious stories can be interesting as well, you don't have to point out that they aren't real, just appreciate the cool story and respect that some people might believe it's real. There really isn't a secret to talking to people, you just have to get comfortable doing it. The trick to making friends is you only have to make one friend, that is the hardest part, then you get to make friends with their friends, since you have someone you both feel comfortable with as a social lubricant it's much easier to feel comfortable talking to someone new.