My question is, why do people who hold these views feel it is OK to change other elements of the religion (e.g. stoning people who commit adultery, not allowing divorce, etc...). I'm just wondering how someone with the anti-gay viewpoint, based on their reading of scripture, would rationalize/justify holding opinions that are antithetical to a strict reading of the bible on these other topics.
I'll try to answer, but as I don't think I've ever gotten a really good response myself [and I'm in CONSTANT communication with conservatives].
I'll give a general explanation. There are two pieces: what is, I think, in fact happening and how they describe it themselves.
I personally don't think that the issue is really about homosexuality. I think that it is more about security in an age of instant communication, and the anxieties of cultural change that piggy back upon capitalism.
Global communication allows for signs and symbols to be sent worldwide, but meaning is still "constructed" locally (for example, what western progressives might say, gets understood in the south as another example of imperialism. Homosexuality, is just an example of us giving it to Iraqis, so to speak). The anxieties that people have about the market and their own relationships gets projected into a very simple issue: homosexuality.
I don't think the presenting issues are particularly new. The big shifts happened when sex, death and property became divorced, in part, due to economic changes (that allowed some women to live independently) and technological advances (birth control). The consequences of sex [a child, or death from childbirth] have changed, and alongside, the choices of women.
Birth control essentially gave women an immense amount of individual power, the consequences of which are still being discovered. It's clearly good for individual women, but since then, the complexities of sexual desire have still not been discerned well by the church.
As women became more powerful, it was a matter of time when gay men found that they had more liberty. By and large, the Episcopal church has essentially moved along with the culture on this - and the Episcopal church represents, I think, a pretty good example of the confusions that people have. Most people (and I think this means the entire culture, actually) haven't figured out exactly what these changes mean for us.
It coupld be a cultural divide. My Indian mother- who was both an aristocrat and a communist, had lots of gay friends. But she said to me, once, "I just could not live with you being gay. Its probably my last inherited bigotry from my Indian culture." It was interesting that she recognized it. There are about 7 Indian pastors in the diocese, and one of them said to me last year, "I just don't understand homosexuality. I just don't get it. I don't know what to make of it." Simply put, the cultural divide is just too vast. We should respect that.
I often hear the following: Conservatives point out that the "plain text" says that church tradition has been unanimous that male gay sex is an "abomination" or unnatural. They then argue that scripture has the tendency of becoming less rigorous liturgically [thus Christians give up many of the Jewish rituals] but more rigorous regarding sex. This argument allows them to avoid the more serious issues in the OT like Usury or keeping the Sabbath.
When a conservative says "2000 years" he is just repeating a fact - yes, the church has pretty much objected to homosexuality. But there are couple reasons why this isn't good enough. Hearkening to the past is a bias rather than a truth. There is no reason to assume that older is better: it is simply a perspective that most people, before capitalism, had. But in the end" we've always done it that way" is a mediocre way to begin an ethic. Scripture seems to offer a better way: is it beneficial [as Paul noted - all things are lawful, but not all things are beneficial]?
Of course, there are numerous arguments also why the liturgical / moral distinction is incorrect, and the argument about sexual ethics being "more rigorous" has more to do, I suspect, with record keeping and the need of the state to have an easy welfare system [a good idea, perhaps, but very utilitarian]. Jesus was strengthening the marriage vow because he was reminding the people that men had hard hearts when they discarded women.
But the crucial reason conservatives offer - the "best" one - has to do with primacy and idealization of the unity and difference of two sexes. Scripture and church tradition seem to have a fairly consistent metaphor about the bride and bridegroom being symbols, for example, the people and the land, or the church and Jesus Christ. To dismiss this metaphor is to trivialize what God intends [which is for us to procreate and have children] for us, and the wisdom of most humanity regarding the natural use of our genitalia.
This is the theological standpoint of the most credible biblical scholar, Robert Gagnon, who opposes homosexuality. Scripture does assume, as does anyone who lives, that male and female are pretty important parts of human identity.
The best response to this is, "No shit."
Personally, I think that the description of church tradition being uniformly anti-gay is probably correct - to a certain point. This is probably because homosexuality was conflated with sexual greed and exploitation. The question then is, what is the purpose of our desires? Christian evolutionists like Joan Roughgarden are challenging the notion that our genitalia are made for procreative purposes first - they might be made, for example, for joy (as, actually the Archbishop of Canterbury argues in one of his earlier essays titled, The Body's Grace).
The other sense by conservatives is that the Episcopal Church, generally, has abandoned something called "The Faith Once Delivered." I can't really explain it to you, because I don't quite understand it myself. It seems to have a very supernaturalistic, puritanical understanding of what the church is for (say, "saving souls" - admirable, but highly reductionistic). It might be that the Nicene Creed seems to be said, but not literally believed, by most bishops or priests. What is true is that the church has decided that the creed has nothing to do with sexuality. They might be right that most bishops and priests interpret scripture in a fashion that would be unrecognizable to those in the first century.
What they err about is that bishops and priests are saying things different than what was thought 100 years ago. The church has had a "liberal" theology for at least 70 years. Perhaps what is changing is that now lay people are reading the same things that I am.
My own view is that the battle for full inclusion of gay and Lesbian people in the Episcopal church has been won by progressives. Most dioceses in the Episcopal church ordain competent gay clergy, quietly. Our actions - distressingly for most conservatives - have moved much faster than our theology. Unfortunately, this tends to also irk liberals who get upset when most bishops are simply trying to hold their diocese together. Of course, as conservative priests get a lot more nasty and start challenging moderate bishops, these same bishops will realize that they have to draw a line somewhere.
As the men in the Anglican tradition dissolve, an interesting counter current is happening. The women from all 38 provinces of the Anglican church are regularly meeting. If you follow the work of the Anglican women, you'll note that they are talking about other issues. And they have said very clearly that homosexuality distracts us from issues of poverty.