What will “God” do if religions have to obey the same laws as everyone else by, say, uniting a pair of homosexuals in holy matrimony? Cause more warming of the Planet? 
Every single one of God’s alleged “laws” came to us…and come to us now in some of these comments…from the mouths and pens of Humans. It’s all hearsay (along with the rest of it). Nevertheless, seeing as how many Humans are residually superstitious, religion still gets all kinds of grandfathered special treatment from the government, including freedom from paying taxes. 
In America, the religious are mostly “just in case” religionists---they suspect it’s probably all bull…and that dead people never actually show up again…but hey, “just in case.”
So why would gays want to get married in a Church that doesn’t approve of their marriage? Oh, they’re Catholic…or they believe in some church. In that case go back and read the first paragraph above.