I am a christian myself. This is how I see it:
First of all, Jesus Christ himself made it clear that 'may the first one that hasn't sinned throw the rock on the woman'. A woman was accused of adultery (if I remember correctly) and Jesus's point was you are all hypocrites to throw stones at her because everyone on earth is a sinner just like she is.
That in mind, we are in no position to judge homosexuals because we all sin regardless. I hold grudges for example, something the bible says you shouldn't do. Some members of my church are even aware of these grudges because I'm quite vocal about them. Does this mean they should deny me the right to get married just because there is something 'unchristian' about me? As I've said myself we even have a gay couple in our church that we welcome as one of our own. That's because everyone sins in some way, and we as mortals do not know which sins are the worst. God decides who goes to heaven and who goes to hell, not us.