This Sixth Commandment is perhaps more famous in its King James Version verbiage than the modern versions which usually translate “You shall not murder” (Exodus 20:13). Whatever dialect you say it in, this commandment stands out starkly from those that come before it. It is short and to the point. One could say it is unmistakably clear, but in fact its scope has been hotly debated.
Some have interpreted “Thou shalt not kill” in absolute terms, using the commandment as a proof text to oppose capital punishment, or even killing animals for food. However, such uses of this verse ignore the wider context in which it was written. The Law of Moses mandated capital punishment as well as the killing of animals for sacrifices and food. There is no way that the law would blatantly contradict itself in this way. Thus, without wading too far into the debate on these social issues, we can conclude that the commandment, “Thou shalt not kill” does refer to the murder of a fellow human being in a civil context.
The vast majority of us live out our earthly lives without ever murdering a fellow human being. Does this make us innocent of the Sixth Commandment? It does not. Just as we saw in our studies of the Second Commandment, one need not create a physical idol in order to commit idolatry. In the same way, the commandment against murder reaches past the physical act into the thoughts of hatred, greed, envy and malice that can lead to murder.
Jesus said as much in a part of his Sermon on the Mount known to theologians as the Antitheses:
“21 You have heard that it was said to those of old, 'You shall not murder; and whoever murders will be liable to judgment.' 22 But I say to you that everyone who is angry with his brother will be liable to judgment; whoever insults his brother will be liable to the council; and whoever says, 'You fool!' will be liable to the hell of fire.” (Matthew 5:21-22)
John made much the same point in his first epistle:
“12 We should not be like Cain, who was of the evil one and murdered his brother. And why did he murder him? Because his own deeds were evil and his brother's righteous. 13 Do not be surprised, brothers, that the world hates you. 14 We know that we have passed out of death into life, because we love the brothers. Whoever does not love abides in death. 15 Everyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.” (1 John 3:12-15)
Cain was the first murderer in the history of the world. He murdered his brother Abel out of anger because Abel’s sacrifice was more pleasing to the Lord (Genesis 4:1-8). According to Jesus and John, we can follow in Cain’s footsteps without even physically harming anyone. If we allow ourselves to be ruled by hatred, anger, insults and arrogance, we are no better than murderers. These are the same negative attitudes that spawn murder (Mark 7:20-21).
In fact, the fear of punishment is likely what keeps a lot of hateful, angry, arrogant people from committing murder. Given the opportunity to commit murder and get away with it, a person ruled by these emotions is likely to seize the chance. But God can read our hearts (Jeremiah 17:10), and in his eyes, the desire to commit sin is as bad as the sin itself. God wants his people to do good and refrain from evil, not out of fear of punishment, but out of love (1 John 4:18). This is why Paul writes that the second half of the Ten Commandments can be aptly summed up by the single commandment, “You shall love your neighbour as yourself” (Romans 13:9).