you missed the point
no, I believe you miss the point. Marriage is not all about procreation: it is a contract that affords certain rights and responsibilities (including but not limited to) visitation rights in hospitals, inheritance of estate, joint ownership of property).
Why should I not be able to enter into such a contract with whomever (consenting adult)I choose. If your religion forbids it, it need not support or conduct it. I do not believe any gays say the Mormon church must conduct gay weddings (not any taken seriously by anyone, anyway)
Someone against inter-racial marriage 230 years ago would have been just as certain the Bible forbids it, just as grossed out, just as certain our whole way of life would crumble, felt just as threatened and under siege as you do with gay marriage...if not more so.