Ugh. Yet another Vichy Conservative.
Did you support dumping DOMA too?
Churches have always had state recognition of their marriages. The state cannot strip something that predates the formation of the state. Giving that up voluntarily will give the state the opportunity to ‘derecognize’ Christian marriages.
The churches did the government a favor when they chose to act as agents of the state. A religious marriage does not make a legal marriage.
The state has a vested interest in knowing the marriage status of people, for everything from inheritance to tax rates.
If the state now has to do ALL of its own marrying, then the cost to the state increases, but so does their influence over the churches. The churches agreed to marry people legally because the state wanted them to - not the other way around.