The Christian Bible is not definitively against homosexuality, nor is it against the marriage of homosexuals. As with most things, it has come down to interpretation.
This is from one of the better written, balanced and researched articles I've found on this subject, written from a retired member of the Baptist ministry.
"There is an interesting note from church history.
[Noted church historian] John Boswell... has discovered that, whereas the church did not declare heterosexual marriage to be a sacrament until 1215 C.E., one of the Vatican Library's earliest Greek liturgical documents is a marriage ceremony for two persons of the same sex. The document dates to the fourth century, if not earlier. In other words, nine centuries before heterosexual marriage was declared a sacrament, the church liturgically celebrated same-sex covenants.9-9"
Chapter 9 of
his paper is titled
Full acceptance by society, including the blessings and legality of marriage should be extended to gays and lesbians in the same way it is extended to others. His entire paper looks at the issues raised here. Appendix A looks at the interpretation of the Bible, B at Hoomosexuality and the Bible, and C at the Three Sins. As there are various discussions happening here, I won't try to summarise a relatively lengthy article. He includes full references.
I included this reference because there are many people adding to this discussion, and perhaps more reading it, that would arguably benefit from reading an account of Christianity in regards to homosexuality that is from a new perspective, many of his statements are interesting, and while I've not yet researched his references in further detail, his focus and and attention to specific biblical references, such as Paul, Leviticus etc, are, at the very least, interesting reading.
As it was mentioned before, in regards to Paul, his stance is perhaps one of misinterpretation also (from the same source, and in regards to I Cor, 6:9):
Malakoi literally means "soft" and is translated that way by both KJ and RSV in Matt. 11:8 and Luke 7:25. When it is used in moral contexts in Greek writings it has the meaning of morally weak; a related word, malakia, when used in moral contexts, means dissolute and occasionally refers to sexual activity but never to homosexual acts. There are at least five Greek words that specifically mean people who practice same-gender sex. Unquestionably, if Paul had meant such people, he would not have used a word that is never used to mean that in Greek writings when he had other words that were clear in that meaning. He must have meant what the word commonly means in moral contexts, "morally weak." There is no justification, most scholars agree, for translating it "homosexuals."
I add this post only to indicate that perhaps one foundation from which theologically driven distaste of homosexuality, as well as its related marriage considerations, is not as solid as expected.
So, if sex should only occur within marriage, and Christian Bible, from which our laws originate, doesn't condemn homosexual marriage, what then?
Now I'm going out, so I've not the time to talk about the non-Christian side of things, so until I wander in here again, keep talking.