Very good point! And indeed religion is like politics here: if you're in a multi-cultural team, it's very likely that some will believe in some god, and some won't, some will have some (strong) political ideas that others won't share.
But at the end of the day, programming is a matter of solving engineering problems, which aren't related in any way to religion or politics.
I let them share their ideas, as long as they accept me sharing mine which might be different. The golden rule (for me) of a healthy team is to have open communication and being open-minded. This is very useful for solving our engineering problems, but it comes out to be also extremely valuable to cope with their wired beliefs and opinion ;D (and they probably think the same of my beliefs and opinions)