James Calder, who seems like a generally sensible fellow, tries to argue that we ought not to legislate morality and that the churches should stay out of politics. You hear this kind of thing a lot, mostly from similarly sensible people.
The trouble is that these slogans are highly muddled. Whatever else the Canada Health Act and the Criminal Code are, they are an attempt to legislate morality, in some cases controversial moral beliefs (such as that the rich should not be allowed to purchase better health care than the poor). And no right-minded person really thinks the Churches should stop complaining about the treatment of refugees, or of mentally-ill homeless people or about the Iraq war. Social justice is rather at the heart of the Abrahamic religions (at least).
James seems to think it is important to the argument that the moral beliefs in question are controversial -- not everyone agrees with them. But politics is all about normative issues people don't agree about. Decriminalizing murder isn't a political issue, because practically no one -- not even the Supreme Court of Canada -- disputes that there should be some limit on people's ability to kill other people. But decriminalizing marijuana use is a political issue precisely because people disagree about the norms involved. So, of course, any political intervention by any religious organization is going to be into issues people disagree about.
Same-sex marriage would hardly have arisen as a demand without some ideas peculiarly Christian in origin. Even as gay-positive a pre-Christian as Plato could never have conceived of same-sex marriage. The idea that marriage must be for love comes from the Protestant Reformation. The idea that natural, biological distinctions between people are spiritually unimportant comes -- in the West at least -- from Christianity as well. The United Church has combined these principles when it says that loving, committed relationships should be treated the same, regardless of biology. It follows from the United Church's principles that same-sex marriage should be recognized, not just by the Church, but by the state.
The Catholic Church has a different view -- but it too is not a simply about the Catholic sacrament of matrimony, but about the social institution of marriage, whether Catholic or not. The Church views marriage -- and for that matter, sexuality -- as primarily about being open to procreation and new life. Marriage doesn't center nearly so much on the autonomy of the adults. You can reject this view of marriage, but in doing so you come up with some difficult moral problems of your own.
Of course we legislate morality. What else are we supposed to legislate?
Disclaimer: For the purposes of getting hate mail from the right sources, the Pithlord wants to state his support for same-sex marriage, regulated freedom of choice on abortion, a pretty milquestoast process theology and vouchers, so Bible-thumping parents can send their kids to be taught things the Pithlord considers anathema. Please rant accordingly.
Update June 27: I wrote this before the news of Nicole Kidman's annulment on the grounds that her marriage to Cruise was a Scientologistic non-marriage. Any Catholic apologists out there want to defend the consistency of that....?
Ross Douthat steps up to the plate.