In concluding this section of his letter, St. James brings the conduct which he has been condemning within the sweep of a very comprehensive principle: "To him, therefore, that knoweth to do good, and doeth it not, to him it is sin." No Jew, whether Christian or not, could plead ignorance as an excuse for his transgressions in this matter. Every human being has experienced the uncertainty of the future and the transitoriness of human life; and every Jew was well instructed in the truth that man and all his surroundings are absolutely dependent upon the Divine will. Moreover, those whom St. James is addressing prided themselves on their spiritual knowledge (i. 19); they were professed hearers of God's Word (i. 22, 23), and were anxious to become teachers of others (iii. 1). Theirs is the case of servants who knew their master's will, and neglected to do it (Luke xii. 47). They themselves declared, "We see;" and the rejoinder is, "Your sin remaineth" (John ix. 41). They knew, long before St. James instructed them on the subject, what was seemly for human beings living as creatures in dependence upon their Creator; and they neglected to do what is seemly. To them this neglect is sin.
The passage is very commonly understood as applying to all sins of omission; and no doubt it is very capable of such application, but it does not follow that St. James was thinking of more than the particular case before him. The words may be interpreted in three different degrees of comprehensiveness, and St. James may have meant one, or two, or all three of them.
1. The relation in which a creature ought to stand to the Creator is one of humility and entire dependence; and he who knows that he is a creature, and adopts an attitude of self-confidence and independence, sins.
2. In all cases of transgression knowledge of what is right aggravates the sin, which is then a sin against light. "If I had not come and spoken unto them, they had not had sin: but now they have no excuse for their sin" (John xv. 22).
3. This applies not only to transgressions, but to omissions. Knowledge of what is evil creates an obligation to avoid it, and knowledge of what is good constitutes an obligation to perform it. The latter truth is not so readily admitted as the former. Everyone recognizes that an opportunity of doing _evil_ is not a thing about which any choice is allowable. We are not permitted to use the opportunity or not, just as we please; we must on no account make use of it. But not a few persons imagine that an opportunity of doing _good_ is a thing about which they have full right of choice; that they may avail themselves of the opportunity or not, just as they please; whereas there is no more freedom in the one case than in the other. We are bound to make use of the opportunity of doing good. "To him that knoweth to do good, and doeth it not, to him it is sin."
Some of those who think that St. James knew the Epistle to the Romans see here an allusion to the principle which St. Paul there lies down: "Whatsoever is not of faith is sin" (xiv. 23). For reasons already stated (p. 57), it must remain doubtful whether St. James had knowledge of that Epistle; and even if he had, we could not by any means be sure that he had it in his mind when he wrote the words before us. But his words and St. Paul's, when combined, give us a complete statement of a great moral principle respecting the possession or non-possession of knowledge as to what is right and wrong in any given case. So long as we have _no_ knowledge that a given act is right, _i.e._ so long as we are in doubt as to whether it is allowable or not, it is sin to do it. As soon as we _have_ knowledge that a given act is right it is sin to leave it undone.