I belong to one. My wife is a Christian and I am not. They do enthusiastically welcome me, which is consistent with what they should be doing in my opinion. Nobody pressures me to act in any way that I am uncomfortable with and rarely (only when I invite it) does anyone discuss my beliefs with me. I think that this church is unusual; they have a huge focus on being a "family". I would have never gone if not for my wife (it would be awkward), but it is very rewarding to me and I get to meet and befriend people who are very different from who I would meet otherwise (as a scientist/programmer type). It also provides many service opportunities and people to help.