Um, Separation of Church and State?
I posted this on Erik's site as a comment response to his question about the bans on gay marriage.
It's been already said, but I guess you are saying my marriage to my wife isn't valid because neither of us believe in God. How we feel about each other would hopefully change your mind in that regard. We weren't married by anyone religious, nor anyone licensed by the court for that matter. In fact, we were married in your new home state, (and my old one) Pennsylvania. We paid ten dollars more for the license, and had to have two witnesses sign instead of one officiant. It was colloquially called a "Quaker" license by the person at city hall.
You might look up some time what the Quakers think about marriage. To them, it isn't important to obtain God's approval of the marriage - instead, what matters is (in addition to how you feel about other, obviously) acceptance by friends and community.
Acceptance of my marriage by your church or faith means nothing to me, whereas acceptance of my marriage by my friends, family, and community does... and acceptance by the government, for the legal and economic reasons.
On the other hand, for a gay couple that did believe in God, it would be important to them for their Church to recognize it. And I have no problem with that Church deciding that their marriage would not be valid, although I'm sure the couple would be distraught.
But the government should not have anything to do with it. The benefits, protections, etc. that the government provides are intended for people who have declared that they wish to be bound by the responsibilites and commitments that come with it. It really should just be that simple.