When a burly stranger approached my wife and me on a street abroad, we shrunk back in fear. Our holiday had been going badly; we had been yelled at, cheated, and extorted from several times. Were we going to be shaken down again? To our surprise, the man just wanted to show us where to get the best view of his city. Then he gave us a chocolate bar, smiled, and left. That little gesture made our day—and saved the whole trip. It made us grateful—both to the man and to God for cheering us up.

What had made the man…