For most of my life, I've been aware of a particular conflict (there are many, of course) between liberal and conservative Christians. I'm going to try to shed some light on this particular difference of opinion.
Which means, of course, that I'll just make people mad. But I persist.
The disagreement, I think, springs from a misunderstanding of the Golden Rule.
Liberal Christians (as I understand them) tend to think the Golden Rule says something it doesn't actually say. They think it says, “Do unto others as you would have them do unto you—and then they will treat you the same way.”
But the text doesn't actually say that. What it says (I'm quoting the NIV here) is, “So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets.” (Matt. 7:12)
You'll note that there's nothing there about outcome. If you pay attention to Christ's teaching as a whole (all the business about taking up crosses, dying, etc.), you'll note that there is very little talk of temporal (that means “having to do with this present world”) benefits. The assumption in Christ's teaching generally is that we're supposed to do what's right, and chances are good we'll see no benefit from it at all. In fact, we're likely to be killed for it. But we'll have our reward in Heaven.
This, I think, is where liberal Christians go wrong when they try to apply the Golden Rule to civil law and international relations. Due to their essential misunderstanding of the (nonexistent) promise of good consequences, they think application of the Golden Rule is the best way to ensure peace and good order in this world. It is not.
Scripture makes it very clear that the king (civil authority) is meant to bear the sword for the protection of the populace. “For he [the authority] is God's servant to do you good. But if you do wrong, be afraid, for he does not bear the sword for nothing. He is God's servant, an agent of wrath to bring punishment on the wrongdoer.” (Romans 13:4)
In other words, the civil authority is meant to be the hero, the strong one who protects the weak. By violence, when necessary.
It's possible to attempt to carry out that hero function through rigorous application of the Golden Rule, letting bad guys off and setting them free to do further injury. The liberal Christian (misunderstanding, as I said, the Golden Rule as promising positive temporal consequences) thinks that such a policy will cause the criminals to have a change of heart and become nice. I maintain, as I said above, that the Golden Rule implies no promise of temporal results. Any civil authority that tries this experiment declaes itself willing to accept injury to, and the murder of, the people it's sworn to protect.
I can find no biblical mandate for the civil authority taking that kind of gamble with the people's lives. Grace is not the king's job. I'm not saying it's always ruled out, but it must be dispensed with great care.
There's a lot of personal satisfaction in being able to see yourself as kind and merciful. But that satisfaction is not worth getting innocent people killed. More than that, it's dereliction of duty.
Lars Walker is a fantasy author. His most recent novel is West Oversea.