MGM, I have often thought the same, but it is wholly dependent on a couple of things. The term marriage must become a constitutionally protected religious term under the establishment clause. The government cannot perform them, or pass laws preferring one means to another. The government cannot also dissolve them, since they did not grant them in the first place. What that would mean to those seeking Marriage is that only the church (denomination, religion, order) in which you were married could grant divorce, if at all. It would be separate from the legal matter; the state could still determine the dissolution of the civil partnership, distribution of property, custody. But your faith group might have a few things to say about whether you were still married or not.
And anyone who merely has a civil partnership cannot claim to be married. And I can preach from the pulpit all I want about how marriage is between a man and a woman, under the 1st amendment. As a Pastor who has a very high bar for whom he will and won't marry, I would gladly agree to leaving Marriage to God, and civil partnership to the government. I think you'll have a harder time convincing gay marriage supporters though; they wont be happy until the government forces God to bless their union. Not being flippant - I have that straight from the horse's mouth.
