I think large, long-lived institutions tend to be conservative, especially about areas they consider their charge. I also think that sexuality is a very emotionally charged topic and people look for rational reasons to back-up their emotional responses. People initially often have an "ick" response when confronted with homosexuality... it's hard for that not to have an affect.
Plus, institutions like marriage do have a big effect on the quality of a child's upbringing. We know that children do better when raised in a stable loving home with two parents (extended family optional). A church should want to foster an environment that is good for its members. Eventually channeling sexual behavior into stable relationships is part of that.
My background is that of an American Evangelical and, as I understand it, homosexual acts are considered sin in the Christian scriptures. If you really stretch and twist, it's possible to interpret it otherwise, but it really is a stretch. Not only is it sin, it's called an abomination, which I believe means really bad sin. Evangelicals and Fundamental Christians (and I use fundamental the way Fundamental Christians mean it) generally put a lot of emphasis on literal interpretations of the scriptures.
Actually, the word translated as "abomination" is perhaps better translated as taboo or "unclean." As is often pointed out, the Bible states that mixed fiber clothing is an abomination, as are shrimp. I think it's hard for all of us (liberal or conservative) to take off our cultural blinders when reading the Bible, since it was written from a very different social context.
In the eighties, when it became clear that the US was becoming more and more secular, a political movement was started in order to attempted to reverse the trend. There have been a handful of areas where attention and energies have been focused. Abortion rights, gay rights, and religious rights tend to be the top ones.
I think there have been time periods of greater secularism in the United States and periods of religious revival ("Great Awakenings" and the like). However, I think the recent focus on abortion and homosexuality (since the Moral Majority in the 80s) has been convenient because those issues are both polarizing and are things done by people "out there in the world." This makes them better issues for fundraising and projection than the previous big evangelical issue of divorce (which was seen as an issue affecting congregations themselves).
That doesn't mean that thoughtful people can't be genuinely against homosexuality, of course.
Like Jennifer said, sex is always a big focus of everything in the US, so here, at least, it's going to get a lot of attention. What I've heard during my years attending church and listening to para-church groups is that homosexual normalization causes the country to slide further away from God and righteousness. Some fear that God will punish a nation that, by their standards, embrace homosexual relationships. I've talked about it with my mother and she pretty firmly believes that, since homosexuals practice one form of sexual perversion, that they are more likely to sexually molest children.
And it's clear why with 1950s "educational" videos like like: [YOUTUBE="A5VNe9NTOxA"]boys beware[/YOUTUBE]
Note that according to most modern studies, homosexuals are no more or less likely to molest people than anyone else. Also note that the gender of children chosen by child molesters made not match the abusers' sexual orientation with adults (if any).
No, if by "sexuality" you mean what a person finds arousing. I see no reason to deny that a person could both recognize the force of teleological arguments against homosexual behavior yet still be aroused by homosexual thoughts or behavior.
As Jennifer mentions, I just don't think those teleological arguments really form the basis of anyone's opinions. They also ignore that "homosexual behavior" is observed in the natural world, as well... as is asexual reproduction and the like. It's blindingly obvious that sexual reproduction is needed for the continuation of any species that only reproduces sexually. However, that doesn't mean that every individual must reproduce sexually—I haven't noticed we human beings having an underpopulation problem—or that not reproducing sexually is wrong.
One could use a similar argument to argue against modern medicine, since it's the nature of pneumonia, influenza, etc to infect and kill weakened people. It's the nature of our immune systems to be strengthened by fighting off infections naturally. It's the nature of an over-populated species to be decimated by plagues, etc.
I don't
feel as though we see it as much here, I expect the fact that our politics are a lot more separated from religion, and we're not as religious as the States would be the reasons why. The figures have
60% of the population here supporting gay marriage.
We just passed the 50% mark of support here in the U.S. (of course that varies a lot from state to state). I think it is the intersection of the religious and political that make the "gay marriage" and "gay rights" debates so tendentious here.
