The law of the LORD is perfect, restoring the soul; the testimony of the LORD is sure, making wise the simple Psalm 19:7NASB
Question 99 of the Larger Catechism, asks, "What rules are to be observed for the right understanding of the ten commandments?" In its answer the Catechism gives eight rules. Here is the first one: "For the right understanding of the ten commandments, these rules are to be observed: 1. That the law is perfect, and bindeth everyone to full conformity in the whole man unto the righteousness thereof, and unto entire obedience for ever, so as to require the utmost perfection of every duty, and to forbid the least degree of every sin." Last week we saw how the Ten Commandments summarize the whole moral duty of all mankind. This week we begin to consider certain rules to ensure that we rightly discern our duty from those commandments.
This question and its answer is one of the reasons why I believe the Larger Catechism is the best document produced by the Westminster Assembly. If you have never read question 99 of the Larger Catechism, I hope you will read the eight articles I plan to write on it. The Catechism's eight rules for rightly observing the Ten Commandments are full of wisdom and practical application for all of God's people of any age. As we have already seen, God's law addresses every aspect of our lives and comprises the sum total of all morality and ethics. Therefore, rightly knowing how to understand and apply those commandments is invaluable to the faithful Christian who wants to please the heavenly Author of them.
The first thing we must remember whenever we are considering any one of God's commandments to us is that the commandment is perfect. God's commandments are never incomplete; they never need some human addition or subtraction to be better. No wisdom of man can improve the commandments of God. If ever we think so, we are the ones who are lacking insight and not the commandments. God's law judges us, we do not judge it. We may misapply the command or misunderstand it, but the fault is always with us, it is never with the commandment of God.
Furthermore, God's commandments bind every human being "to full conformity in the whole man unto the righteousness thereof." What this means is that there are no exceptions to God's commandments. You cannot have a legitimate reason to be excused from the required duty. Neither can any man claim any exception to full obedience in the whole man. In other words, it is not OK for me to do my duty half-heartedly because I am tired, or not feeling well. I may need to call in sick to work, but I cannot call in sick to the moral duty God requires of me, regardless of whether I am in critical condition in the hospital or in perfect health running a marathon. The righteousness required by the law never changes for anyone for any reason, precisely because every human being is equally and unchangeably in the image of God. For God to require less of you in any area would by definition mean that you are less human than other people, and if you are less than human, than it would be wrong for human rights to be given to you. Suddenly, being excused from our duty as humans does not sound so attractive, does it?
Thus, the righteousness required of all mankind is "entire obedience forever." Entire obedience means without anything lacking or missing, and forever means forever! So, for example, when God requires spouses to be faithful to one another, the requirement is to the "utmost perfection" of obedience. No man (or woman) can claim obedience to this commandment who allows his eyes to wander, or his heart to flirt. It is not enough to refrain from outward adultery. "Utmost perfection" requires the most perfect obedience that can be imagined, in heart, mind, words, and actions. Similarly, "the least degree of every sin" is condemned by every one of God's perfect laws. Little white lies are not permissible, neither is convenient forgetting, rationalizing, excusing, or whatever. As James declares, to stumble in one point of the law is to be guilty of all (James 2:10). God's law is perfect. It includes all circumstances and all persons of all times. There are no exceptions and no excuses. To create even one would ultimately result in the most inhuman monstrosities imaginable. If we are going to rightly apply God's law to our lives we must begin with this rule before our eyes and in our minds. As we do so, the psalmist promises that God's law will restore our souls, and make us; simple ones that we are; wise unto salvation!