The law reveals sin (v. 7). “By the law is the knowledge of sin” (Rom. 3:20). “Where no law is, there is no transgression” (Rom. 4:15). The law is a mirror that reveals the inner man and shows us how dirty we are (James 1:22-25). Note that Paul did not use murder, stealing, or adultery in his discussion; he uses coveting. This is the last of the Ten Commandments, and it differs from the other nine in that it is an inward attitude, not an outward action. Covetousness leads to the breaking of the other commandments. It is an insidious sin that most people never recognize in their own lives, but God’s law reveals it.

The rich ruler in Mark 10:17-27 is a good example of the use of the law to reveal sin and show a man his need for a Savior. The young man was very moral outwardly, but he had never faced the sins within. Jesus did not tell him about the law because the law would save him; He told him about the law because the young man did not realize his own sinfulness. True, he had never committed adultery, robbed anyone, given false witness, or dishonored his parents, but what about covetousness? When Jesus told him to sell his goods and give to the poor, the man went away in great sorrow. The commandment “Thou shalt not covet” had revealed to him what a sinner he really was! Instead of admitting his sin, he rejected Christ and went away unconverted.