Here's a thought that struck me today; I don't usually go in for chucking blame around in these cases, but I don't think it's really the fault of Dan Savage or anyone else who's ever accused all Christians of being illiberal jerks (NB Richard Dawkins aside - I can't stand that guy!). It's not their fault because my fellow Christians brought it down on all our heads. How? By saying that they are homophobic because they're Christians. If loud-mouthed, judgemental reactionaries decide to justify their opinions as being rooted in their religious beliefs, then it's not surprising that the people they are crusading against will come to think that only bigots follow that religion.
Once you look at it in this light, it's pretty clear that this is total balls. Sure, some religions are crazy proscriptive and will tell you what to think, what to wear, who to give all your money to and which suicide method to use, but Christianity is not one of them. It's a massive, ambiguous mess of tradition, custom, mythology, warring factions and hopelessly tangled scripture. That's one of the reasons I'm a Christian, actually - I'm pretty sure that my particular beliefs can be slotted in there somewhere. To point at this crazy-paving of a belief system and claim that it absolutely forbids gay people from getting married in clear and unmistakable language is like pretending you can read messages in silly string.
I'm not going to say that which religion you belong to is a choice. This was the case for me, but I don't think it always is. However, a religion ought to be a moral framework. Choosing one, therefore, ought to work around your personal ethics and what 'feels right'. If you genuinely feel that Christianity forbids gay marriage, but you yourself don't have a problem with gay marriage, then perhaps, just perhaps, Christianity isn't the religion for you?
This all amounts to a very long-winded way of saying something simple: I can't come up with a single compelling counter-argument to the position that people who say that they can't support gay marriage because they are Christian are really saying that they don't want to support gay marriage and being Christian is their excuse.
Sticking to your guns when you're sure you're right - even in the face of condemnation and derision - is admirable, and even if I'm sure you're wrong I will respect your views. Personal morals are complicated, and in the end, you can't help how you feel. But trying to hide behind my religion? Not ok.