Of course, what gay couples want is social acceptance. That, they will not receive until the predominant religions of the society alter their stand and good luck with that. Legal rights, to which every citizen is entitled, and cultural rights should not be confused. The governing body should get the hell out of the "holy" matrimony business and, simply, enforce its laws and civil contracts.
The government should, no more, tell a citizen who he may live with than they should tell a church what they may believe. Legalizing gay marriage is an affront to religion and forbidding gay union is an affront to the citzenry. Gay couples will have to gain social acceptance on their own. The best their government can do is stay out of their bedrooms and personal decisions.
All marriages are civil contracts. Try getting a legal divorse from your pastor. It is time to recognise the difference between legality and piety.