Folks on this blog have been making this argument for some time. Here’s a first-rate piece on the subject from Christianity Today. A snippet:
We cannot very well argue for the sanctity of marriage as a crucial social institution while we blithely go about divorcing and approving of remarriage at a rate that destabilizes marriage. We cannot say that an institution, like the state, has a perfect right to insist on certain values and behavior from its citizens while we refuse to submit to denominational or local church authority. We cannot tell gay couples that marriage is about something much larger than self-fulfillment when we, like the rest of heterosexual culture, delay marriage until we can experience life, and delay having children until we can enjoy each other for a few years.
In short, we have been perfect hypocrites on this issue. Until we admit that, and take steps to amend our ways, our cries of alarm about gay marriage will echo off into oblivion.
Read the whole thing.