Foes of gay marriage are primarily motivated to block laws permitting the activity because they interpret their religious texts as prohibiting the practice, and they wish to impose their religious beliefs on the rest of society. Isn't it strange then that there are a number of churches that support and perform gay marriage ceremonies? To those who place their homophobic church ahead of their country and the rights it represents, there can be few bigger thorns in the side than a church that decrees gay marriages to be fine in the eyes of God, no matter what the state may say about them. We would do a great deal to disrupt the message of the homophobes by vocally supporting those churches that are supportive of gay marriage.
Recently, when Washington D.C.'s mayor, Adrian Fenty, signed the bill legalizing gay marriage in the nation's capitol, he did so at a rather surprising location - at the All Souls Unitarian Church, a church that supports and performs gay marriages. This act signified the recognition that there are indeed churches that do not subscribe to the bigoted interpretation of a book which, frankly, is famous for being able to say whatever a given interpreter wants it to say about anything.
Although one fear expressed by the bigots is that their precious church will be forced to perform gay marriages (the last step before the government forces the bigots themselves to enter such unions), there does not seem to be much support for the freedom of churches to perform gay marriages. This is where we must highlight the contrast. Because there are churches that support and perform gay marriages (link, link, link) or at least that officiate same-sex wedding ceremonies even in states that give them no legal credit.
But wait, isn't that the state discriminating against the church? Surely the church is the authority on who is wed "in the eyes of God," and what right does a state have to refuse to recognize the matrimonial binding conducted in a properly incorporated church of that state? It will tie the right wing in some uncomfortable knots to be reminded that there are churches that perform gay marriages,to know that these churches have the vocal support of their communities, and that the message coming forth from this support is that gay marriage is fine by churches, but it is the government that is denigrating these houses of God by failing to accord respect to the rites performed there. True, the ultra-bigoted among the right will have no compunction against attacking churches with which it disagrees, but in the eyes of the less insane public at large, this will distill disagreement over the issue to an internecine dispute within the religion, one for which the state should err on the side of allowing marriages sanctioned by the more enlightened and progressive churches.
In sum, viewed in this way, legalizing gay marriage is not opposing religion, but supporting the freedom of religion. Including the freedom to be married wherever a church will bind in vows.