In Matthew 5:22 Jesus tells his listeners that the person who calls his brother “Fool!” is in danger of hell fire. This, he claims, is the idea implied in the command not to murder.
What then to make of the fact that Matthew records Jesus himself using the word “fool” (Gk. moros, from which we get the word “moron”) on at least two occasions: once to rebuke the Scribes and Pharisees (23:17) and once at the close of the sermon on the mount to describe those who do not follow his words (7:26)?
Reading the passages that woodenly ignores the nature of Jesus teaching. Craig Keener notes that “Most hearers understood that such general principles expressed in proverbs and similar sayings needed to be qualified in specific situations; most legal interpreters also recognized that even biblical laws had to be qualified under some circumstances.” Sometimes people really are fools and it needs to be said.
Ironically, those who would accuse Jesus of living a double standard on this issue have missed the very point Jesus is trying to make in the passage. He is not setting up a new law that forbids using the word “fool.” He is expressing the kingdom inappropriateness of relationship breaking attitudes and words. Acting as if it is a new law that Jesus himself has broken is to fall into the trap of thinking that kingdom living can be reduced to rules that we keep.
Living the kingdom life is not and, indeed, cannot, be about abiding by hard and fast rules, though there are certainly boundaries that must not be crossed. It wasn’t even that way in the OT. There, the wisdom literature addresses living the fullness of the covenant life that laws cannot adequately cover. Now, we live out the law, not by living by the law but by living by the Spirit.