How do We Determine What Should be Legal or Illegal?

In the mail today I received a sermon manuscript from John Piper.  It is a manuscript of a sermon that he delivered on June 16, 2012 on the topic of homosexual marriage.  Also included was a letter of response to the Star Tribune after they reported that Piper refused to direct his congregation on the issue of gay marriage.  You can read Piper's response to the Star here.

In fact, if you take the time to listen to/watch/read Piper's sermon, it's very clear what his stance is, and what the stance of the Bible is.  It makes one wonder how the Star Tribune could have goofed it up so badly.  The sermon is an excellent, biblical defense of why marriage is only between one man and one woman.  I highly commend it to you.

What interested me the most about the sermon, however, were Piper's comments about how we as a society determine the legality of things.  This is an issue that was recently raised on this very blog by a commentor to this post.  The commentor says:

My question to you is, why should our law for the country need to be based upon the word of God when our country does not have a national religion and many of its citizens do not believe in God?  I am a devout Christian, but many in America are not.  Why do you believe it is fair or permissible to have American laws which affect everyone based upon your particular religious beliefs?

In essence, the commentor asks, "Why should laws be based on your (the Bible's) morality?  It's a fair question, and one that I think has a logical answer.  I responded thusly:

The reality is that all of our laws are based on some form of morality.  The only question is who's morality we base our laws upon.  Most of our laws are based on Christian principles.  So we can't say that we don't or shouldn't base our laws on religion, because all laws are based on religion.  Again, the question is, upon which religion's standards should we base our laws?

What I am trying to communicate in this answer is that all laws have a moral foundation.  That is, we always base our laws on some model of morality.  The question comes down to which system of morality we keep in view when making our laws.  So to argue that Christians shouldn't legislate morality is not a good one, because all laws essentially legislate morality.

This is an idea Piper expounds upon in his sermon, although he does it more wordily and sounding much smarter than I do.  He makes the point that "Deciding which actions will be made legal or illegal through civil law is a moral activity aiming at the public good and informed by the worldview of each participant."  What follows is him expounding on this statement.

How should Christian citizens decide which of their views they should seek to put into law?  Which moral convictions should Christians seek to pass as legal requirements?  Christians believe it is immoral to covet and to steal.  But we seek to pass laws against but we seek to pass laws against stealing, not against coveting.  One of the principles at work here seems to be: the line connecting coveting with damage to the public good is not clear enough.  No doubt there is such a connection.  God can see it and the public good would, we believe, be greatly enhanced if covetousness were overcome.  But finite humans can't see it clearly enough to regular coveting with laws and penalties.  This is why we have to leave hundreds of immoral acts for Jesus to sort out when he comes.

Laws exist to preserve and enhance the public good.  Which means that all laws are based on some conception of what is good for us.  Which means that all legislation and all voting is a moral activity. It is based on choices about what is good for the public.  And those choices are always informed by a worldview.  And in that worldview - whether conscious or not - there are views of ultimate reality that determine what a person thinks the public good is.  

Which means that all legislation is the legislation of morality.  Someone's view of what is good - what is moral - wins the minds of the majority and carries the day.  The question is: which actions hurt the common good or enhance the common good so much that the one should be prohibited by law and the other should be required by law?  

So how do we determine what should be legal or illegal in our society?  We vote in ways that represent our morality, motivated by our worldview.  In this sense, all laws are religious laws - Christian or otherwise.