Homosexuality was well known in the ancient world, well before Christ was born and Jesus never said a word about homosexuality. In all of his teachings about multiple things -- he never said that gay people should be condemned. I personally think it is very fine for gay people to be married in civil ceremonies.
I draw the line, maybe arbitrarily, in requiring by law that churches must marry people. I'm a Baptist, and I believe that each congregation is autonomous and can govern its own affairs. So if a local Baptist church wants to accept gay members on an equal basis, which my church does by the way, then that is fine. If a church decides not to, then government laws shouldn't require them to.
I don't actually have a problem with allowing churches to pass on marrying gay and lesbian couples either. Divorced people can't get married in a Catholic church. Some faiths won't allow those who don't follow their beliefs to get a religious ceremony. Big deal.
It's the piece of paper and government recognition of rights that's important. Religion is all a bunch of arbitrary beliefs based on superstition. I'll take what I can hold in my hand versus what I can hope for in the afterlife.