It's definitely something that needs to be addressed before you get too serious. I think you could get along fine as an atheist with a religious partner, or one with a religious family. Just be open. Not many functioning couples are 100% in agreement on everything anyway.
But when it comes to how to raise kids... That's something that you need to think seriously about when considering marriage (if that's the end goal anyway). I get along great with religious, non religious, superstitious, etc, people but I think it would be a different story when it comes to raising children. Can't relate to that though, so... good luck!
