@  if you've got something to say to me, I'd prefer it if you'd address me personally, rather than some disembodied, abstract "some people".
“Do unto others as you would have others do unto you” (Matt 7:12) - I actually take this very seriously, hence my comments about being torn on the issue of gay marriage. I actually don't want gay people to be unhappy, but I think gay marriage causes more problems than it solves.
My problem is that I don't see a win-win scenario. Gay marriage seeks to redefine and re-orientate marriage around a person's private felt needs, rather then the public, lawful institution that has served the public good for millennia over a very broad range of social and religious contexts .
I don't subscribe to "slippery slope" cliches, but having achieved the objective of redefining marriage to satisfy felt needs, I can't see how you can mount a legal defence against expanding the definition of marriage to include felt needs in other possible combinations. If you were to reduce the criteria down to nothing more than a "stable, loving relationship", then you necessarily have to accept yet more stable, loving relationships involving any number of permutations of sexes, numbers of people (from 1 to infinity, inclusive), parents and children and even species. The issue is not whether the individuals involved feel that their needs are being met in whatever bedroom they choose to sleep in, but whether these relationships ought to be cemented and affirmed in law, with all the privileges and responsibilities that comes with marriage. That's why I see this proposal as a dissolution of marriage.
So, my being torn goes something like this; imagine yourself in 1930's Britain, and you are concerned about the well-being of your neighbors over the north sea, who are evidently in turmoil. I would write something like, "Dear Germany, I would like to see you living in a stable, safe living-space (lebensraum) and I don't wish to interfere with your aspirations for a happy and fulfilled life, but invading Poland is the wrong way to go about getting it."
Finally, I find any appeal to history to support gay marriage lacking credibility.
There's a brief survey of ancient Greaco-Roman attitudes in the recent publication "Sexegesis" as follows (citations removed for brevity, but you can look them up from the preview here http://www.sexegesis.com/
"In the ancient world, one can find mixed things said about homosexual sex and same-sex relationships. In the Graeco-Roman world, generally speaking, same-sex relationships between women were routinely condemned, while homosexual acts by men were tolerable, though it was thought shameful for a man to allow himself to be the passive or penetrated partner in the sexual act. Still, other Greek and Roman authors regarded homosexual acts with disdain. Juvenal mocked the drunken debauchery of women that often led to lesbian sexual acts. The Socratic tradition of both Plato and Xenophon condemned homosexual acts. The Old Testament resoundingly rejects homosexual practice (Lev 18:22; 20:13) and the rejection is continued in post-biblical Jewish literature as well. For instance, the author of the Epistle of Aristeas typifies Jewish attitudes to pagan sexuality when he states that: “For they not only have intercourse with men but they defile their own mothers and even their daughters.” In Sibylline Oracles the author condemns the Phoenicians, Egyptians, and Latins who “hold unholy intercourse with boys."'
So, even if the prohibitions of Lev 20:13 are nothing more than a reflection of extant attitudes, then the worst that can be said of them is that they reflect the conservative end of the spectrum. That's not so different from the situation that we find ourselves in today. Plus ca change, as the French would say.
I find it significant that although ancient attitudes might have varied much as they do today, there appears to have been no widespread or sustained support for canonizing these sexual relationships into marriage.
What is clear is that the push to move same-sex relationships into the territory of marriage is unprecedented in history. Some believe that it's the dawn of a new age of enlightenment; I see it as the invasion of Poland.
I've said enough, but I have previously written to Kevin Rudd on the matter, and got a response, which you can find here, if you're interested.