I am not convinced that gay marriage approval poses any threat to religion or our society.
For one thing, it is miniscule in percentage of the population.
It is huge in it's ramifications for Christianity based society and Western civilization, but those consequences are in the future so most people don't notice them today.
For another thing, the fight for it was symbolic more than real as not that many gay couples take advantage of it because marriage imposes obligations as well as rights.
The vast majority of homosexuals have not the slightest interest in monogamy or marriage. I try to get people to look at their culture from their perspective, but it is difficult for normal people to grasp.
Imagine that you were a young boy surrounded by young attractive girls that just wanted to have sex with you. That is life in the "gay" community, except the girls are boys, and have a very strong male sex drive. In San Francisco's "bath" houses, homosexuals would have 10 sexual partners on an average visit.
In homosexual circles, having a thousand sex partners is not unusual. It is in fact, part of the lifestyle.
So yeah, "Gay Marriage" was a symbolic victory, and nothing else. It was an effort to force normal people to accept something perverted, whether they liked it or not.