I hesitate using the phrase Separation of Church and State because it is often overused and its meaning is skewed. The idea that the Church (encompassing all religions and faiths) and the State should be separate was not to protect the State, but to protect the Church. However, it necessarily applies to this issue.
When I took French, I learned about how France has marriage and civil unions, where marriage is both a religious ceremony and a State-sanctioned status between a man and a woman, and civil unions were solely State-sanctioned and could be between any two individuals, regardless of sex. I thought this was the perfect solution to the oppression of gay couples; marriage, by definition, is a man and a woman, but the government should allow the same rights through a civil union.
The civil union designation also doesn’t create problems like common-law marriage, where two roommates or friends who live together for an extended period of time may find themselves “married,” even if that was not their intention. However, it doesn’t solve everything, because there is still a gap between the rights granted to a marriage and the rights granted to a civil union.
But marriage (between a man and a woman) has always been a religious ceremony. Which leads me to the conclusion that perhaps the State has overstepped its bounds all these many years by recognizing marriages and by the ability to go to the courthouse and get married. So if we were to revise all laws that refer to marriage to instead say ‘civil union,’ our problem would go away. After all, the argument is that all of it should be referred to as marriage… why don’t we just refer to all of it as civil union.
With this, the State is not given the erroneous power to define what is and isn’t marriage. After all, we don’t allow the State to define what is and isn’t communion or what is and isn’t a funeral vs. a memorial service, etc. So, marriages remain between one man and one woman, unless of course a religion decides to amend this of their own accord, and civil unions are State-recognized and afford the same rights to homophilic and heterophilic couples.