If God doesn't want any homosexuals

If God wants us to irradicate homosexuality then one of the most effective ways for us to do it is for us to not just tolerate gay marriage, but to actively encourage it.

There is some sort of genetic base for homosexuality. That doesn't mean that genetics determines sexuality. It's possible it's both genetic and a lifestyle choice in that it might be that genetics only makes it a viable lifestyle choice for those with the genetic predisposition to find it an attractive thought. But even if it is a lifestyle choice, there's still a genetic base.

By discriminating against homosexuals and by not allowing gay couples to form families we cause many gays to reproduce who wouldn't do so if the society was more tolerant of homosexuality.

So by encouraging gay unions we'd be reducing gay reproduction and doing God's will if it's true that God really hates gays.

So, God wants gay marriage and only haters of Jesus would oppose it.