10 For whosoever shall keep the whole law. What alone he means is, that God will not be honored with exceptions, nor will he allow us to cut off from his law what is less pleasing to us. At the first view, this sentence seems hard to some, as though the apostle countenanced the paradox of the Stoics, which makes all sins equal, and as though he asserted that he who offends in one thing ought to be punished equally with him whose whole life has been sinful and wicked. But it is evident from the context that no such thing entered into his mind.
For we must always observe the reason anything is said. He denies that our neighbors are loved when a part only of them is through ambition chosen, and the rest neglected. This he proves, because it is no obedience to God, when it is not rendered equally according to his command. Then as the rule of God is plain and complete or perfect, so we ought to regard completeness; so that none of us should presumptuously separate what he has joined together. Let there be, therefore, a uniformity, if we desire rightly to obey God. As, for instance, were a judge to punish ten thefts, and leave one man unpunished, he would betray the obliquity of his mind, for he would thus shew himself indignant against men rather than against crimes; because what he condemns in one he absolves in another.
We now, then, understand the design of James, that is, that if we cut off from God’s law what is less agreeable to us, though in other parts we may be obedient, yet we be come guilty of all, because in one particular thing we violate the whole law. And though he accommodates what is said to the subject in hand, it is yet taken from a general principle, — that God has prescribed to us a rule of life, which it is not lawful for us to mutilate. For it is not said of a part of the law, “This is the way, walk ye in it;” nor does the law promise a reward except to universal obedience.
Foolish, then, are the schoolmen, who deem partial righteousness, as they call it, to be meritorious; for this passage and many others, clearly shew that there is no righteousness except in a perfect obedience to the law.