Here's how I see the answer to gay marriage vs. christian mentality:
Make marriage not a legal ceremony. Seperate the church from the state. Nothing changes in a marriage, you're simply joined in the eyes of God. That way, the courts have no control over marriage, the states don't have to recognize anything, and we set up another legal union that everyone has to get. Straight or gay, you have to go to a "justice of the peace" basically, get legally joined and thus get those special rights that married couples get now.
Seperate marriage from state unions. It's simple, in my opinion.
It's not special rights, it's equal rights. That way, no one can complain.