I am sure that it has not escaped all of you debating that the power to "marry" people is delegated to the official performing the ceremony by the government. In the early days it was delegated from the King, or appropriate potentate. I always liked the word "potentate"
Thus government has not encroached on marriage it had commingled with it since early days.
But as Mr. Gude so eloquently pointed out it is a civil union, a contract, thus falls under the laws and jurisdiction of the government. If marriage were viewed as simply a church thing to dissolve a marriage would a) Be impossible IAW the Bible ( Something I for one, and DJ, Larry, RR, Pixie, and thousands of other people who are happily divorced, am damn happy is not the case. -or- b.) You would get divorced by a priest, reverend or whoever waving their hands over your head and dividing stuff however THEY saw fit without legal jurisdiction from the Gov.
In our Republic our elected officials (the judiciary is not elected) have not seen the need to legitimize something that is NOT the will of the people. One day perhaps the House and the Senate will all gather on the Mall and in a moment of divine enlightenment dance about in joyous celebration and make it legal. Until that time I guess you will have to lump it.
Like it or not there are many people who just think that homosexuality is immoral, unnatural and just plain bad. Their opinion counts just as much and is just as much correct as those homosexuals who want their lifestyle legitimized by the government.