Imagine there was no tenth commandment. We might pretend to faithfully obey each of the other laws. The rich young ruler did. Jesus asked him about each command from the second table of the law—except the last. The ruler answered, “All these I have kept from my youth.” But when Jesus forced him to examine his desires, he wasn’t so confident (Luke 18:18–23).
How can the command that seems the least outwardly harmful be the most revealing? Because our desires, even more than our actions, are basic to who we are. We are what we want. Some of the sins we would never do we desperately want to do. A technically “faithful” man might passionately desire his neighbor’s wife. The apostle Paul knew that he was a sinner—that he violated all of God’s laws—because his desires were wrong (Rom. 7:7).
Because the tenth commandment demands that we examine our passions, it also provides an opportunity to test our relationship to all the commandments.
How Does the Tenth Commandment Work?
In condemning covetousness, the tenth commandment doesn’t name a new sin. Instead, it warns against “even the slightest desire or thought contrary to any one of God’s commandments.” Truly “The best way to keep men from committing sin in act is to keep them from desiring it in heart.”[i]
We might have expected a different answer; such as: God “requires full contentment with our own condition with a proper and charitable frame of spirit toward our neighbor, and all that is his.”[ii] That’s a good answer. It’s wrong to pursue the good desire for intimacy through adultery or fornication, or even to fantasize about such sins. We may not satisfy the noble desire for acquiring wealth by taking what belongs to our neighbor, or even by envying his possessions. So moderating our good desires by contentment with our current lot is part of what the tenth commandment requires.
But the tenth commandment also regulates our attitude toward God. Our misplaced cravings reveal spiritual brokenness. Discontent with God was the root of the first human sin. Adam and Eve—having no actual unmet needs—sinned by suspecting that God was withholding something from them, and by acting out that suspicion (Gen. 3:5). They were unhappy—not with their circumstances, but with God. “The highest good of people in this life cannot be obtained from goods” but from God.[iii] Still, our doubts about his sufficiency lead us to seek satisfaction in what can never satisfy. Wrong desires are enslaving, the very thing God doesn’t want for his people (Exod. 20:2).
The only cure for covetousness and its rotten fruit is to become satisfied with God and his providence. When we delight in God, we can appreciate what we have without craving more; God is enough for us. The rich young ruler’s external conformity to the law was meaningless because he wasn’t satisfied with Jesus. Only by contentment with God in Christ can we happily “live in the bodies we have, in the houses we own, with the husband or wife God has given us, with the jobs we have.”[iv] Material contentment—the obvious demand of the tenth commandment—requires spiritual contentment.
Because of its summary character, the tenth commandment also provides the perfect segue to evaluating the law’s role in our sanctification.
How Do the Ten Commandments Work?
What use it is to study God’s law if we always come short of its holy standard?
The law leads us to Jesus.
Studying God’s law helps us confirm 1 John 1:8. We sin. We are idolaters, false worshipers, blasphemers, Sabbath breakers, authority despisers, murderers, adulterers, thieves, liars, and coveters. “Nothing good dwells in me, that is, in my flesh” (Rom. 7:18). “We deny not that the keeping of the law is true righteousness: but as no one performs it, and never has performed it, we say, that all are excluded from it, and that hence the only refuge is in the grace of Christ.”[v] Only by knowing our sin can we hunger and thirst for Jesus’s righteousness (Matt. 5:6) to which the law witnesses (Rom. 3:21; 10:4). Knowing our weakness, we pray for God’s renewing grace, believing that “if we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9).
The law guides believers in holy living.
We cannot “keep these commandments perfectly.” The more we know of God’s law, the more we agree that “In this life even the holiest have only a small beginning of this obedience” (cf. Eccl. 7:20). Still, “with all seriousness of purpose” believers must and do “begin to live according to all, not only some, of God’s commandments.” We can’t do them on our own. We desperately need God to sustain in us this “seriousness of purpose.” We need the Spirit to make sin more offensive and godliness more desirable. With God’s help, we do become “wholeheartedly willing and ready from now on to live” according to his holy will (Q&A 1).
The law helps us anticipate a sinless eternity.
The law is one way God portrays his purity and the possibility of real sinlessness. Believers long for a life where, both within and without, sin and its desires are eradicated and obedience is complete. In our struggle for faithfulness, let’s remember that there is a glorious finish line. As Jesus finished the race in victory, so will every believer. Christ is bringing a day when the “full deliverance” of the elect shall be perfected. “Therefore we expect that great day with a most ardent desire, to the end that we may fully enjoy the promises of God in Christ Jesus our Lord.”[vi]
The law is frustrating because it is perfect. It reveals our guilt because it reflects Christ’s beauty. It tells us we have not yet arrived by describing what life will be like when Christ completes his work in us (Phil. 1:6). No mere creature has perfectly kept the law. But Jesus has. For us. And he’s helping us keep it too. And one day even our desires will finally align with God’s.