Here’s another great inbox question:

In Jesus’ denunciation of the Jewish leaders in Matthew 23:16-22 he calls them fools twice. The Greek word is moros. This same word was used in Matthew 5:22 where Jesus said that anyone who calls someone a fool (moros) is liable to fiery Gehenna. Is Jesus violating His own command? 

Or does 5:22 apply only to the Kingdom? If so then Jesus would still be inconsistent because 5:22 is clearly intended for His disciples and is part of their instructions about being good disciples now. 

Thoughts? 

Two things come to mind: 

1. The issue in Matt 5:22 is clearly some sort of personal beef where an angry person during Millennium calls someone else (likely not a believer since the words “his brother” are not found in the third statement of verse 22) a fool. That is not at all the issue in Matthew 23. In Matthew 23 the Lord is rebuking a class of people—legalistic self-righteous unbelievers. The issue is different. 
2. People guilty of certain offenses are called fools by God quite often in both Psalms (six times) and Proverbs (63 times). The one who says there is no God is a fool. Those who hate knowledge are fools. Fools mock at sin. A fool despises his father’s instruction. It is not likely that the Lord was trying to say that only God can rightly call people fools. And even if He was saying that, since He is God (John 1:1) He is certainly correct whenever He uses the word fool (moros).  

In his 1915 commentary on Matthew, Alan Hugh McNeile says, “That the word moroi is attributed to Jesus, in spite on Matt 5:22, is striking; it shews that not the word but the spirit in which it is uttered is what matters” (p. 334). 

Geisler and Howe make this helpful observation: 

In Matthew 5, [fool] is used in the context of someone who is “angry” with his brother. Neither Jesus nor Paul [Gal. 3:1; 1 Cor. 15:36] harbored hatred toward those to whom they applied the term. Thus, their use of the term “fool” does not violate Jesus’ prohibition against calling others a fool (http://defendinginerrancy.com/biblesolutions/Matthew_23.17.php). 

At the Answers in Genesis website this answer is given:  

If you were to study each biblical example where God calls someone a fool, you will find a righteous reason behind it. When Jesus called the Pharisees and scribes fools in Matthew 23:17, He explained that they were satisfying themselves instead of giving glory to God. They glorified the gold in the temple rather than the temple of God that housed the gold, which is foolish. 

At the Apologetics Press website this explanation is on target,  

Keep in mind that when God expressed His contempt for someone by calling him a fool, He did it with complete, accurate knowledge that the one to whom He attributed foolishness was, in reality, a fool. Accusations made by God (through the Bible writers) are not born of unrighteous anger, but of intellectual knowledge, divine consideration, and a desire for fools to turn from their prodigal ways (2 Peter 3:9). We, however, must restrain ourselves when, in frustration or anger, we consider calling someone a fool without a just cause. It is possible to be angry without sinning. Paul wrote: “Be angry and do not sin: do not let the sun go down on your wrath” (Ephesians 4:26), and Jesus experienced righteous anger (Matthew 21:12; Mark 3:5; cf. Psalm 7:11). We must be sober when we are angry, never letting unjust and hurtful criticism or slander against others slip from our lips (Matthew 12:36). 

Therefore, even in the Millennium it would be appropriate under certain circumstances to call someone a fool. It would be inappropriate when a person is mad at someone for some personal reason. But it would appropriate to call someone a fool if he was saying there is no God, if he was rejecting parental instruction, or if he was teaching false doctrine.