I was talking with The Frau on this issue. She tells me that in Germany, everyone who wants to get married first goes through a secular civil ceremony that established the legal state of marriage. After that, if the couple wishes, they can go through a church ceremony to establish the religious state of marriage. Whether they can get a religious ceremony is up to the specific church.
If that's the way they do it in Germany, that seems like the perfect solution as it clearly separates the legal and religious states of marriage. That is the problem in the US. For so many years, in the context of marriage, the division between the legal and religious states of marriage has been intertwined; when they should be separated.
The government should not control religious marriages, and churches should not control secular legal marriages.
As for gay marriage; no one has ever been able to explain to me how allowing gays to marry will somehow denigrate heterosexual marriage.
Perhaps we should ask Kim Kardashian or Britney Spears about the sanctity of heterosexual marriage?