Here's an excerpt of a chat with Mike Horton in the Washington Post from some months ago:
San Francisco, Calif.: Last week at my Catholic church in northern California, numerous people got up and walked out when the pastor urged the congregation to vote for Proposition 8 during his sermon.
If you think there should be one, where should the line be drawn today between church and state on issues like Prop 8 and others?
Rev. Dr. Michael S. Horton: There is a big difference between preaching, teaching, and applying God's Word to God's people and enforcing that Word through specific policy prescriptions. As a minister, I can say that's it's a strange and terrifying thing to step into a pulpit and speak in God's name. It's downright dangerous, not because of the people's judgment but because of God's. Am I really saying what he has told me today, right here in this passage today? Or am I full of hot air? Am I respecting the limited authority he has given me by his Word or am I using it as my own bully-pulpit to vent my opinions?
I am obliged by this Word to teach that marriage is a divine ordinance established between one man and one woman, but I do not believe that I have any divine warrant for binding the consciences of God's people to vote for or against a particular policy regarding the state's proper ordering of the common life of my neighbors. I've discussed this proposition with a number of friends and colleagues and even though we hold the same view of marriage as divinely instituted, there are differences over specific public policies.
I suspect that my views probably aren't the dominant ones, but I see legal marriage in much of the Western world as basically a form of shortened paperwork for name-changes. That sort of practice seems to be getting a boost in recent years - but it's a cultural thing that you won't find in every society. (I think that Korea is the typically cited example there, but there are other countries where such is also common). Other than name-changing - a cultural matter - the paperwork around marriage seems pretty much pointless. "Common law" relationships are fairly well established in law, and pretty much everything else is taken care of even prior to the year or so that takes to come into effect. Even outside "common law" relationships, you don't need to be married to win what's effectively a divorce. While bigamy is technically illegal, the courts also don't seem to have much of a problem with it. Theoretically, polygamy is outlawed, but a mistress seems to have same legal standing as a spouse (another version of this story here), so as longer as you don't legally marry a second spouse the government doesn't seem to have a problem pretending you did.
Simply getting rid of the paperwork and forms surrounding marriage licenses etc, and you seem to solve a fair number of problems. The rationale for this is something like the following:
Far more than marriage, divorce by its nature requires active government intervention. Marriage creates a private household, which may or may not necessitate signing some legal documents. Divorce dissolves a private household, usually against the wishes of one spouse. It inevitably involves the state -
including police and prisons - to enforce the divorce and the post-marriage order. Otherwise, one spouse might continue to claim the protections and prerogatives of private life: the right to live in the common house, to possess the common property, or - most vexing of all - to parent the common children.
- Excerpted from Stephen Baskerville, Taken into Custody, p. 75/76
Interestingly, this also seems to fit the example you find in the Old Testament. Divorce involves paperwork (or perhaps you need to chisel out a certificate on a stone or do something with clay or ...), but marriage doesn't seem to.