Gay marriage and the search for a clear Christian perspective

I have been working on this issue in my head for a while.
Australia, while not exactly at a crossroads, is certainly feeling the eagerness of the gay lobby to make gay marriage a point of public debate. As well it should be.

So if the essence of that debate is to hear both sides, I sure wich I had heard or could write down a coherent Christian perspective on it.

It's worth noting, should anyone read this, that the debate is not Gays vs. Christians.
No. Yet Christians seem the only group called on for their opposing view. (Right-wing conservatives are too but always seem to invoke God sooner or later.)

And for most Christians the idea of widening marriage to include same-sex couples is uncomfortable.

Now, I am just looking for a better explanation, from Christians, of why society should prohibit same sex couples from marrying, beyond the argument that it contravenes the Bible's family model and thereby makes us uncomfortable.

I am eager to get comments on this from Anyone.
Will post more later.
Luke
Sent via BlackBerry® from Telstra