The law of God must not just be the rule of our obedience, but also the reason of it.  We must not simply obey the law, but obey it because the Lord requires it; we must do what it says out of love for God; the love of God must be the fountain, the impulsive, and the efficient cause of all our obedient to the law (see 1 John).

Although the Ten Commandments in their biblical form (in Ex. 20 and Deut. 5) are quite short, their meaning is deep and broad.  Using other Scriptures, we can properly talk about how to interpret the Ten Commandments.  For one example, the Westminster Larger Catechism in Q/A 99 talks about biblical rules for the right understanding of the Ten Commandments.  For another example, Edward Fisher echoed those rules in his Marrow of Modern Divinity.  These rules for interpreting and applying the Ten Commandments are helpful; I’ll give an edited/summarized version of Fisher’s rules below.  (Note: though Fisher didn’t give a list of proof texts, he was clearly alluding to Scripture in his discussion, so I’ve added some texts for further thought.)

1) Every commandment has both a negative and affirmative part contained in it.  That is, where an evil is forbidden, the contrary good is commanded, and where any good is commanded, the contrary evil is forbidden (Deut. 6:13, Mt. 4:9-10, Mt. 15:4-6, Eph. 4:28, etc.).

2) Under one good action commanded, or one evil action forbidden, all of the same kind or nature are comprehended; yea, all occasions and means leading thereunto.  [For example, ‘do not commit adultery’ includes the forbidding of lustful looks that lead to adultery; consider the David and Bathsheba story.]

3) The law of God is spiritual, reaching to the very heart or soul, and all the powers thereof, for it charges the understanding to know the will of God; it charges the memory to retain, and the will to choose the better and to leave the worse; it charges the affections to love the things that are to be loved and to hate the things that are to be hated.  It bids the powers of the soul to obedience, as well as the words, thoughts, and gestures [which arise from the heart – Mt. 22:37-39].

4) The law of God must not just be the rule of our obedience, but also the reason of it.  We must not simply obey the law, but obey it because the Lord requires it; we must do what it says out of love for God; the love of God must be the fountain, the impulsive, and the efficient cause of all our obedient to the law (see 1 John).

5) Just as our obedience to the law must arise out of love for God, so it must also be directed to a right end – that is, that God alone may be glorified by us.  Otherwise obedience is not the worship of God, but hypocrisy.  In seeking to please God in our obedience, we glorify him, and these two things always go together (1 Cor. 10:13).

6) The Lord does not only take notice of what we do in obedience to his law, but also the manner in which we do it.  Therefore we must seek to obey the law after a right manner – that is, humbly, reverently, willingly, and zealously (cf. Mic. 6:8).

Or, put in a different yet parallel way, the Heidelberg Catechism goes like this:

What do we do that is good?  Only that which arises out of true faith, conforms to God’s law, and is done for his glory; and not that which is based on what we think is right or on human tradition (Q/A 91).

For the above quotes by Fisher, see p.275-276 of The Marrow of Modern Divinity.

Rev. Shane Lems is a minister in the Orthodox Presbyterian Church and services as pastor of Covenant Presbyterian Church in Hammond, Wis. This article appeared on his blog and is used with permission.