What does Matthew 5:22 mean?

Jesus is demonstrating to His listeners how the righteousness of their spiritual leaders, the scribes and Pharisees, is not enough to earn heaven. They superficially obey and teach the law of Moses without any kind of heart-change. Jesus is teaching God's intent behind the commandments of the law. In particular, Christ is pointing out that unrighteous attitudes and thoughts, while not exactly the same as unrighteous actions, are just as much worthy to be labelled as sins.

Christ has pointed out well-known commandment not to murder (Exodus 20:13) and the civil judgment for those who do: death (Numbers 35:31).

Now Jesus contrasts the statements of Israel's spiritual leaders with a more complete understanding. Jesus' teaching. "But I say" is the phrase He will use to show where God intends mankind to focus their obedience to these commands. In this case, Jesus says that obedience to the commandment against murder begins with eliminating anger for one's brother. In context, one's brother would be a fellow believer, or a relative, or any close associate.

In the moment these words were spoken, they would have been shocking. Even today, they are deeply challenging. Jesus is saying that an improper attitude—to be unrighteously angry with another person—makes one subject to God's judgment. Who can honestly claim they have never been angry towards someone else? Or that every unhappy thought was perfectly justified? It's convicting and even frightening to think that level of perfection is God's standard for right and wrong.

Jesus acknowledges that someone who insults another risks judgment from other men. By this, Jesus may have meant that someone who is angry enough to insult another must answer not just to God, but to government, such as the council of Jewish religious leaders. Even in the ancient era, speaking unkind words could result in legal problems. The term Jesus uses here is rhaka, originally a Hebrew word which can mean "fool" or "empty head."

Next, though, Jesus escalates this teaching even further. The original phrasing of this verse uses the Greek term mōre, used as a slur like calling someone a "moron," or an "idiot." Whether Jesus means the same level of insult as the prior phrase, or something worse, the point is clear: being angry enough to insult another makes a person liable to the "hell of fire." The word "hell," in this case, is translated from the Greek word geenna, a reference to the ever-burning trash dump outside the city, used as a symbolic reference to eternal damnation.

Jesus is showing that God cares about actions, but He cares most about the heart. The reason for the command not to murder is given in Genesis 9:6, "Whoever sheds the blood of man, by man shall his blood be shed, for God made man in his own image." If being made in the image of God makes it wrong to murder, it also makes it wrong to call a person "worthless." Guarding the heart, and the mind, is just as much part of obedience to God as good behavior.

Only those with perfect righteousness will be welcomed into eternity with God based on their deeds; Jesus' examples are quickly demonstrating that no human person can claim perfection.