Just think about that for a moment. What the hell does a civil "marriage license" mean in a religious institution -- or, in the case of the Catholic Church, a sacrament?
I look at marriage like one might look at conception of life. The government should not define it regulate it or limit it but simply acknowledge it to protect it. No-fault divorce in my opinion is comparable to abortion. In both cases government stepped in and added 50 shades of gray to what should be black or white issues THEN premised upon the created gray areas began to define and regulate.