We are considering various aspects of the sixth commandment this week as we look at the Heidelberg Catechism's exposition of this statute in questions and answers 105–107. Today's passage is one of the texts cited in this section of the catechism, and it shows the expansiveness of the commandment against murder. Lest there be any doubt that Reformed confessions and catechisms such as the Westminster Standards and the Heidelberg Catechism go too far in applying the Ten Commandments to so many actions and attitudes, our Lord Himself demonstrates the scope of God's law in Matthew 5:21–26.
As we consider Jesus' teaching, let us understand that our Savior is not denying the abiding force of the sixth commandment. Since Jesus, in the same context as today's passage, quotes statements that add to what the Old Testament actually says (v. 43), He cannot be dealing with the commandments as written. Instead, He is addressing misunderstandings and misapplications of the Mosaic law. Today's passage deals with several misunderstandings, not the least of which is the idea that we have kept God's commandments if we observe them in a woodenly literal fashion. Many people in the first century believed they had obeyed the sixth commandment as long as they never killed anyone. Christ's response to this sentiment indicates that such obedience, while necessary, is not enough.
God's law deals with our hearts and our actions. The Lord gave the sixth commandment to forbid the taking of innocent life and to condemn attitudes that lead to actual, physical murder. John Calvin writes, "The hand, indeed, gives birth to murder, but the mind when infected with anger and hatred conceives it" (Institutes 2.8.39). Murder requires hatred—if there were no anger and hatred, there would be no murder. Our hearts must be upright, for while unjust anger that never produces violence is "better" than unjust anger that moves a person to kill, we still break the sixth commandment if we hold grudges and hate others (Matt. 5:21–26).
Question and answer 106 of the Heidelberg Catechism are surely correct to note that the sixth commandment teaches us to hate things such as "envy, hatred, anger, and vindictiveness." May we resist these vices and thereby please our Father.
The sixth commandment does not forbid all anger, for there is a place for righteous anger, as we will discuss next week. But the sixth commandment warns us that what we consider righteous anger may very well be sinful anger, and we must guard our hearts lest bitterness and unjust anger take root. We must implore the Spirit to help us forgive others and to make us willing to hear His conviction when we are feeling unjust anger.