I'm gay and I've spent a decade and a half studying all the world's Faith.

I fully understand what you're saying, however you're not understanding that religion is merely an advent of Faith. The act of marriage is given many names by many places, and the idea you're posing would allow discrimination against cultural equivalents of the bond between two humans, named by Europeans as "marriage." Surely, it's ridiculous to look at a "marriage" between two Jewish people or two Muslim people should be seen as lesser for the fact that they call it something different, have completely different rites, and represent distinctly different understandings of that bond.

The bond of Faith in Love that humanity has uniformly conceived is not bound by the vessel of a name. Calling it "marriage" is merely a performance that gestures at a vague notion; the name "marriage" is not sacred, the bond is.

Remembering that we also live in the context of modern society; the religious understanding of "marriage" has very little to do with the term that society is employing. Society has, at large, adopted English; the English word for that bond is "marriage" and nothing less. Marriage is an English term, not a religious one. This is really the source of consternation, in my opinion; the religious and the societal are fighting for dominion of that word.

Rather than making a new term for the broadly adopted English language and subsequently demanding your ideology reign supreme over all others, maybe have a new term for yourself. English is a language that represents, and therefore belongs to, a wide variety of people; demanding that "marriage" exist as a term that conforms to Abrahamic religions is nonsensical. Use the language of your religion to make a new word.

Then, after you have your new word, make it represent all the gay-discriminating nonsense you want it to.

Before you do, though, consider that Faith in Love is at the essence of what the "gay community" believes in, and remember that a holy man is still nothing more than a man.