Eight Rules for the Right Understanding of the Ten Commandments: WLC Question 99

The Ten Commandments are simple enough for a child to memorize, yet deep enough to examine every part of our lives. Because we are sinners, however, we are often tempted either to weaken God’s commandments or to limit them to outward behavior. The Westminster Larger Catechism helps us avoid these errors by giving us eight rules for the right understanding of the Ten Commandments.

Question 99 asks, “What rules are to be observed for the right understanding of the Ten Commandments?”

The answer is:

“For the right understanding of the Ten Commandments, these rules are to be observed:

1. That the law is perfect, and it binds everyone to full conformity in the whole person to the righteousness of it and to entire obedience forever, so as to require the utmost perfection of every duty, and to forbid the least degree of every sin.

2. That it is spiritual, and therefore reaches the understanding, will, affections, and all other powers of the soul, in addition to words, works, and gestures.

3. That the same thing, in various aspects, can be required or forbidden in several commandments.

4. That when a duty is commanded, the contrary sin is forbidden, and when a sin is forbidden, the contrary duty is commanded. In the same way, when a promise is added, the contrary threat is implied, and when a threat is added, the contrary promise is implied.

5. That what God forbids is never to be done; what he commands is always our duty, but not every particular duty is to be done at all times.

6. That under one sin or duty, all of the same kind are forbidden or commanded, together with all the causes, means, occasions, appearances of it, and provocations to it.

7. That if something is forbidden or commanded to ourselves, we are bound, in accord with our roles in life, to work so that it may be avoided or performed by others, in accord with the duties of their roles in life.

8. That in what is commanded to others, we are bound, in accord with our roles and callings, to help them to do; we are also to beware of partaking with others in what is forbidden them.”

   
   

These rules remind us that the Ten Commandments are not a shallow checklist. They are a complete summary of the moral law and a searching revelation of what it means to love God and our neighbor.

The Ten Commandments Require Perfect Obedience

For a right understanding of the Ten Commandments, we must first recognize that God’s law is perfect. When God rewrote the commandments upon the stone tablets, they were the same words that had been written before: “the Ten Commandments” given by God himself (Deut. 10:4; Ex. 34:1–4).

God does not require partial sincerity or occasional obedience. He requires complete conformity to his righteousness throughout our entire lives. The law therefore forbids even the smallest sin and requires the fullest expression of every duty.

This should humble us. None of us has rendered such obedience. Our failure points us away from self-righteousness and toward Christ, who perfectly obeyed where we have failed.

The Ten Commandments Reach the Heart

God’s law addresses more than visible behavior. It reaches our thoughts, desires, motives, affections, words, and actions.

Jesus demonstrated this when he taught that sinful anger belongs to the territory of murder and lustful desire to the territory of adultery. A person may appear outwardly obedient while inwardly nurturing hatred, pride, envy, or impurity.

The right understanding of the Ten Commandments therefore requires honest self-examination. We must ask not only, “What have I done?” but also, “What have I desired, loved, intended, and imagined?”

The Ten Commandments Overlap

The same action may relate to several commandments because sin rarely remains neatly confined to one category.

David’s sin against Uriah involved coveting, adultery, murder, deception, and the misuse of authority. One sinful desire produced violations of several commandments.

Likewise, one righteous act may fulfill several duties. Faithful generosity may express love for God, care for one’s neighbor, proper stewardship, and freedom from covetousness. The commandments work together because they describe one unified life of holiness.

Every Commandment Includes Its Opposite

When God forbids a sin, he also commands the opposing duty. When he commands a duty, he also forbids the opposing sin.

The commandment against stealing does not merely tell us to avoid taking what belongs to another. It also calls us to honest labor, faithful stewardship, generosity, and concern for our neighbor’s property. The commandment against murder requires more than avoiding violence; it calls us to preserve life, pursue peace, and love our neighbor.

Jesus summarized the law positively: love God with all your heart, soul, and mind, and love your neighbor as yourself (Matt. 22:37–40).

Every Duty Has Its Proper Time

What God forbids is never permissible. We may never lie, steal, worship idols, or commit adultery. What God commands is always our duty, though not every duty must be performed at every moment.

Prayer is always our duty, but we are required to do more than simply pray. Providing for our families is always our duty, but there are also proper times for worship, rest, and service.

Wisdom recognizes which duty our present circumstances require. One responsibility should not be used as an excuse to neglect another.

The Ten Commandments Address the Path to Sin

God forbids not only the final act of sin but also its causes, occasions, provocations, and appearances.

We must therefore avoid the paths that commonly lead us into temptation. A person seeking purity should not deliberately consume material that inflames lust. A person struggling with anger should not continually rehearse offenses. A person tempted toward gossip should not invite conversations centered upon the failures of others.

The right understanding of the Ten Commandments teaches us to fight sin before it fully develops.

The Ten Commandments Include Our Responsibilities to Others

Our obedience is not merely private. According to our particular roles, we should encourage others to do what is right and help prevent what is sinful.

Parents must teach and discipline their children. Church leaders must instruct and shepherd the congregation. Employers must not pressure workers to act dishonestly. Christians should encourage one another toward faithfulness.

We cannot control every decision another person makes, but we are responsible to use our God-given influence faithfully.

The Ten Commandments Forbid Participation in Another’s Sin

We must not only avoid committing sin ourselves; we must also avoid helping, approving, encouraging, or benefiting from the sins of others.

At the same time, we should help others perform the duties God has given them. We should make obedience easier rather than harder for our families, churches, coworkers, and neighbors.

The right understanding of the Ten Commandments therefore asks more than, “Did I personally do wrong?” It also asks, “Did I encourage wrongdoing, remain silent when I should have spoken, or hinder someone from doing what was right?”

Understanding the Ten Commandments Through Christ

These eight rules reveal how broad, spiritual, and searching God’s law truly is. The Ten Commandments reach every action, word, thought, desire, relationship, and responsibility.

Such a standard leaves no room for boasting. It exposes our sin and shows our need for the perfect righteousness of Jesus Christ. Yet for those who belong to Christ, the law is not merely an accuser. It becomes a gracious guide showing us how redeemed people may love God and love their neighbors.

The right understanding of the Ten Commandments should therefore produce both humility and devotion. We should see more clearly why we need Christ, and we learn more fully how to walk in thankful obedience to him.

Soli Deo Gloria