The Larger Catechism
99. Q. What rules are to be observed for the right understanding of the ten commandments?
A. For the right understanding of the ten commandments, these rules are to be observed:
- That the law is perfect, and bindeth everyone to full conformity in the whole man unto the righteousness thereof, and unto entire obedience forever; so as to require the utmost perfection of every duty, and to forbid the least degree of every sin.
- That it is spiritual, and so reacheth the understanding, will, affections, and all other powers of the soul; as well as words, works, and gestures.
- That one and the same thing, in divers respects, is required or forbidden in several commandments.
- That as, where a duty is commanded, the contrary sin is forbidden; and, where a sin is forbidden, the contrary duty is commanded: so, where a promise is annexed, the contrary threatening is included; and, where a threatening is annexed, the contrary promise is included.
- That what God forbids, is at no time to be done; what he commands, is always our duty; and yet every particular duty is not to be done at all times.
- That under one sin or duty, all of the same kind are forbidden or commanded; together with all the causes, means, occasions, and appearances thereof, and provocations thereunto.
- That what is forbidden or commanded to ourselves, we are bound, according to our places to endeavour that it may be avoided or performed by others, according to the duty of their places.
- That in what is commanded to others, we are bound, according to our places and callings, to be helpful to them; and to take heed of partaking with others in what is forbidden them.
Scriptural Defense and Commentary
…  Job 13:7-8. Will ye speak wickedly for God? and talk deceitfully for him? Will ye accept his person? will ye contend for God? Romans 3:8. And not rather, (as we be slanderously reported, and as some affirm that we say,) Let us do evil, that good may come? whose damnation is just. Job 36:21. Take heed, regard not iniquity: for this hast thou chosen rather than affliction. Hebrews 11:25. Choosing rather to suffer affliction with the people of God, than to enjoy the pleasures of sin for a season.  Deuteronomy 4:8-9. And what nation is there so great, that hath statutes and judgments so righteous as all this law, which I set before you this day? Only take heed to thyself, and keep thy soul diligently, lest thou forget the things which thine eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them thy sons, and thy sons’ sons.  Matthew 12:7. But if ye had known what this meaneth, I will have mercy, and not sacrifice, ye would not have condemned the guiltless.  Matthew 5:21-22, 27-28. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire…. Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. Matthew 15:4-6. For God commanded, saying, Honour thy father and mother: and, He that curseth father or mother, let him die the death. But ye say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou mightest be profited by me; And honour not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition. Hebrews 10:24-25. And let us consider one another to provoke unto love and to good works: Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching. 1 Thessalonians 5:22. Abstain from all appearance of evil. Jude 23. And others save with fear, pulling them out of the fire; hating even the garment spotted by the flesh. Galatians 5:26. Let us not be desirous of vain glory, provoking one another, envying one another. Colossians 3:21. Fathers, provoke not your children to anger, lest they be discouraged.
Rule 5: Always Forbidden and Always a Duty
Too often, we are tempted to limit the scope of God’s law. Given the nature of redemptive history and revelation, we can easily historicize the demands of divine law. We can argue that many of God’s laws only pertained to Israel and no longer apply to the NT people of God. If however, the law of God is the moral expression of God’s will then its demands can never diminish over time. The fifth rule says in part “that what God forbids, is at no time to be done.” Prohibitions of idolatry, adultery, murder, etc. are always forbidden. Idolatry is never permissible. Adultery and murder have been forbidden since creation. King David was guilty of both and the NT prohibits the same.
Let us probe this a bit more. A little boy may be deemed “cute” for his boyish evasions and lies. Obvious to all, the little boy breaks the ninth commandment (bearing false witness). It is no less wicked in a little boy than in an older man. Time will not minimize its full prohibition. Adultery, privately committed in the heart is forbidden at all times, no matter what the circumstances (in prison, separated from spouse, ill treated by the spouse, etc.). The moral law is always binding.
Vos offers a good example for this point. He notes how the principle contradicts a “popular” opinion in our culture. “According to this popular notion, it may be right to do something which God forbids, provided we do it for a good purpose. For example, it may be right to tell a lie to save some person’s life; or to gain money by gambling in order to donate it to foreign missions; or to maintain a gambling scheme in order to raise money to support the church.” (Vos) In Islam, a Muslim is permitted to lie to advance the cause of Allah.
Job challenges his “friends” by asking, “Will you speak falsely for God and speak deceitfully for him?” (Job 13:7) Job is accusing them “of twisting the truth to make him [Job] appear wrong and God right. He assumes that they fail to realize that the use of deceit never advances God’s cause.” That is, we cannot lie or deceive even as we try to exonerate God. The end does not justify the means. Remember what is prohibited in Rom. 3:8. Should we say, “Let us do evil, that good may come?” No, what God forbids is at no time to be done.
The opposite therefore is true. That means “what he commands, is always our duty…” Moses chose rather to suffer than to sin: “Choosing rather to suffer affliction with the people of God, than to enjoy the pleasures of sin for a season.” (Hebrews 11:25) This remarkable point should not be glossed over. Many convince themselves that their “hardships” somehow minimize their required obedience. “I don’t have to be patient and loving because my health or circumstances are so overwhelming.” Other examples could be offered (various circumstances, peculiar predicaments, etc.) but we must conclude that we are always required to obey God’s law
The last clause can be confusing because it seems to contradict the very point it sought to establish: “and yet every particular duty is not to be done at all times.” The divines were much more nuanced in their understanding of the moral law. The verse used to support this interpretive rule is Matt. 12:7, “And if you had known what this means, ‘I desire mercy, and not sacrifice,’ you would not have condemned the guiltless.” In this passage, Jesus cites Hosea 6:6 to expose their misunderstanding of the Sabbath. Ritual adherence to the law (in this case, the observance of the fourth commandment) should not outdo or supplant compassion or mercy. Some things are more important than others and they have their proper place. Not every law can be obeyed at all times in the same way. Ridgley says, “It is always our duty to visit the sick, comfort the afflicted, defend the oppressed; but such objects do not always present themselves to us, so as to render it our duty at all times.” Vos offers the example of the Sabbath: “Some duties are specifically limited to certain times, as, for example, Sabbath observance. But even the duties that are not so limited are not to be done all at once. We are to rejoice with them that rejoice, and to weep with them that weep, but not both at the same time.” (Vos)
Rule 6: Same Kind Forbidden or Commanded
The sixth rule can easily bother our flesh. It reads, “That under one sin or duty, all of the same kind are forbidden or commanded; together with all the causes, means, occasions, and appearances thereof, and provocations thereunto.” Our tendency is to flatten the commandment and play the literalist. Our reasoning can look like this: “Murder is killing someone. So, as long as I avoid taking someone’s life, I should be fine. Physical harm or abuse therefore may be permitted as long I don’t kill.” The sixth rule addresses this kind of reasoning. In the heat of sin, our wicked hearts can easily reason like this.
Jesus takes this on forcefully and clearly. In Mt. 5:21-22, 27-29 we read these words:
You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ 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.… “You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.
Here, anything that leads to murder is forbidden. Anger can be the means or cause, etc. of murder. Insulting someone wounds the person verbally. These are related sins and can be the means of leading into the forbidden sin. We are called to abstain from all appearances [or kind] of evil (1Thess. 5:22). Every “kind” of evil should be avoided (the word can denote “appearance” but “only in the sense of external appearance that reflects internal reality”). God desires adherence to His Law in thought, word, and deed. Vos explains that “…any particular act in our outward life is not something isolated, by itself, but the product of a complex chain of events and motives. Thus the commandment which forbids the sin of murder is interpreted by Jesus as forbidding the sin of hatred, which is a cause of murder. And the commandment which forbids adultery is interpreted by Jesus as forbidding the sin of lust, which leads to adultery.”
Even provoking someone to commit a forbidden act can be a breach of that commandment. “Let us not become conceited, provoking one another, envying one another.” (Gal. 5:26) Here, the provoking means to challenge someone (to combat or athletic contest). To provoke someone to anger and the numerous sins that anger spawns are forbidden. We might not have committed the act but we provoked or incited the evil in the other person. They disobeyed but we engineered their disobedience. This can happen through words, manipulation, gestures, etc. Fathers must not provoke their children to anger (Col. 3:21). Wives can easily provoke their own husbands and vice versa. The husband cannot excuse his anger because she provoked him but she also remains guilty because she provoked this sinful behavior.
 John E. Hartley, The Book of Job (NICOT; Accordance electronic ed. Grand Rapids: Eerdmans, 1988), 220.
 Thomas Ridgley, A Body of Divinity, vol. 2 (New York: Robert Carter & Brothers, 1855), 313.
 Gene L. Green, The Letters to the Thessalonians (PNTC; Accordance electronic ed. Grand Rapids: Eerdmans, 2002), 265.