Kristor offers insight as usual on the Orthosphere: “Sex in Church.” I highly recommend it. From the brief essay:
The West went off the rails when we began to think that the symbols of our liturgies supervened upon physics, as merely conventional epiphenomena thereof, and as therefore deficiently real, or material, or important, so that we could with impunity make of them whatever we wished. In truth, of course, the supervention runs the other way: physics supervenes upon, and is itself a symbolon of, that Truth to whom liturgical symbols all refer, and intend, and from whom they are derived; so that all importance, all material, all phenomena are enactions of those symbols, or of their functions, implicates, and corollaries. And you can’t control the Truth, for he controls you, absolutely. No matter what you think or do, he is in fact your Lord. If you try to mess with him, you only mess up yourself.
Recently, I was arguing with a friend over “homosexual marriage,” and my friend asked whether the Church should allow marriage for sterile men and women who are incapable of procreation. I replied that it should (as it does), even though one of the chief roles of marriage is for the creation and raising of children. For marriage is more than a social institution, albeit the foundation of society, and more than a biological necessity for the continuation of the race, though it fosters human survival and allows for human flourishing. For marriage is primarily a reflection of truth—that is, a reflection of God and of God’s providence. The masculine and the feminine are not social constructs or grammatical conventions but distinctions at the heart of being. As Saint Maximus (along with the wise from many religions) reminds us, man is the microcosmos. Human beings are God’s keystone on the edifice of the universe that crowns and recapitulates all the motifs of the overall structure—and it is no architectural flaw that we are male and female. Likewise, marriage is central to God’s impressive design—a masterful synthesis of those complementary patterns. “Same sex marriage” is not only sterile, but its sterility is a consequence of its absurdity. For it fails to instantiate marriage at all—it misses the mark completely. It can only grossly parody the unification of the masculine and the feminine in a manner similar to the way the stage can only imaginarily represent love or virtue. Yet, drama recognizes this shortcoming, as do its participants and audience. The abomination of our age has no such sobriety—or modesty.