“You have heard that our ancestors were told, ‘You must not murder. If you commit murder, you are subject to judgment.’ But I say, if you are even angry with someone, you are subject to judgment! If you call someone an idiot, you are in danger of being brought before the court. And if you curse someone, you are in danger of the fires of hell. So if you are presenting a sacrifice at the altar in the Temple and you suddenly remember that someone has something against you, leave your sacrifice there at the altar. Go and be reconciled to that person. Then come and offer your sacrifice to God.” (Matthew 5:21-24)
When Jesus said, “But I say,” he was not doing away with the law or adding his own beliefs. Rather, he was giving a fuller understanding of why God made that law in the first place. For example, Moses said, “You must not murder” (Exodus 20:13); Jesus taught that we should not even become angry enough to murder, for then we have already committed murder in our heart.
The Pharisees read this law and, not having literally murdered anyone, felt righteous. Yet they were angry enough with Jesus that they would soon plot his death, though they would not do the dirty work themselves.
Killing is a terrible sin, but uncontrolled anger is a great sin too, because it also violates God’s command to love. Anger is a subject well-discussed in the Bible. While anger itself is not wrong—after all, God shows anger—uncontrolled anger is. Anger in this case refers to a seething, brooding bitterness against someone. It is a dangerous emotion that always threatens to leap out of control, leading to violence, emotional hurt, increased mental stress, and spiritual damage.
Uncontrolled anger starts with an attitude. Jesus wants us to practice thought-control as well. We will be held accountable even for our attitudes. Paul’s advice in 2 Corinthians 10:5 can help you exert control over your thoughts. Another way to exert control is to meditate on Scriptures—to “fix your thoughts on what is true, and honorable, and right, and pure, and lovely, and admirable. Think about things that are excellent and worthy of praise” (Philippians 4:8). You’ve got an advocate: the Holy Spirit. He’s the master of control.