Whew, I'll give it a shot, though the question is a bit ambiguous, IMHO. Basically, I support people expressing whatever views they like so long as they don't commit or advocate violence. Within private organizations I generally support them setting whatever policies they want. In public communities, I support equal protection under the law, which means you have to grant the same rights and privileges to everyone unless there's a compelling mitigating factor (e.g. if you've been convicted of armed robbery three times you've forfeited the Second Amendment rights with which you demonstrably can't be trusted. ) Thanks to the First Amendment, religion doesn't qualify as a compelling mitigating factor, but for the rules of the religion itself it obviously does.

Culture doesn't give people an out for me. I understand quite well that opposition to gay sex (but not homosexuals themselves, a subtle but important distinction) is generally agreed to be part of Christian culture and happen to think it correct for various reasons not really relevant here. It should not be a part of American culture, because not every American is a Christian, there is growing debate within the Church about the historical opposition to gay sex and even if neither of those things were true the country is run by the Constitution, not the Church, for good reason. Others are free to publicly and vocally disagree with me, and I will respond by telling them why I think they're wrong. If they start assaulting homosexuals I'll call the cops.

So I support opposition to gay sex within the Church and oppose that opposition in America as a whole, because I believe that's the ethically correct thing to do in each case. Note that widespread opposition to gay sex is predominant in both cultures, but only acceptable to me in one. It's not because the cultures are different, but because Christianity entails a number of commitments that being an American does not, and gay sex is not, IMHO, reconcilable with those commitments. That's not a cultural distinction, it's a defining one. If I decide I don't like rock music I'm discarding part of American culture; if I change my citizenship to Norwegian I'm no longer an American.