Marriage and sexual intercourse are not equivalent terms for the paradigm of ‘male and female’. If they were, then the corresponding understanding of human nature would be exclusivist. It would place those male–female relations in which neither marriage nor coitus is a part into a subordinate position and the humanity of all those unable or choosing not to enter such relations in question. The elderly, the impotent, the widowed, the celibate, the hermaphrodite, the transsexual, the deformed and handicapped, and the homosexual would have their humanity and the humanity of their interrelationships denied them. The creation narratives do afford some special status to procreative, and therefore potent, heterosexual relations; however, procreation is construed as a blessing which is bestowed not primarily on individuals but on the species so that it can continue through generation. In short, this way of understanding the image provides no basis for the exclusion of the homosexual, the single and the variously infertile from the image.Luke (who I've been talking with often on this blog) posted this elsewhere as an example, I think, of thoughtful and thought-provoking discourse on the subjective of gay marriage. His comment was that some conservatives would no doubt find even this passage objectionable.
I could go on about why this is the case, but I'll just skip to a central point: this 'excluding these people from humanity' line is, put frankly, a load. No, these people are not having 'their humanity' stripped from them. 'Their interrelationships'? Rather depends on what in the hell that means, as the modern academic is typically incapable of talking about sex in a way that makes it easy to linguistically tell "fucking" apart from "holding hands". In fairness, conservative Christians are often the same way, likely for different reasons.
Perhaps the best, if fastest, response is that one way to actually deny someone their 'humanity' is to treat their handicap as something other than a handicap. When the deaf person is viewed as 'functioning normally' - that there is nothing about them, physically, which is in need of healing, which has gone awry - we really are denying them their humanity in a relevant way, precisely by failing to recognize where they stand as humans. It's a bit like convincing a fallen being that they, in fact, are not fallen after all. This may make them feel better - even better than they felt back when they thought they were, in fact, fallen or handicapped in some way - but it's still a kind of robbery.
Blunter still would be this response: few people involved in this debate give much of a shit about 'relationships' or even 'love*'. It's the fucking that drives the debate, thank you. Always has, always will. Tell the a GLAAD activist that you have no problem with two men loving each other, so long as they sexually abstain, and do not expect to find an ally in your proclaimed position. Expect some fury.
(* I'm reminded of a Sam Kinison line. Paraphrased: "I've had a change of heart about sex recently. I don't believe in just having sex for pleasure, no, I think you should only have sex when you're in love. ... Now, it may be for a very short fucking time..!")
Edit: Also, Luke - beg pardon for my coarse language here. Not intended to be offensive to you. I just happened upon this and wasn't too enamored with the tone. Longstanding dislike of mine on this topic.