Therefore to him that knoweth to do good, and doeth it not, to him it is sin.

To him therefore who knoweth to do good, and doth it not, to him it is sin.

To him therefore who knows how to do good, and does it not, to him it is sin.

to him, then, knowing to do good, and not doing, sin it is to him.

If, however, a man knows what it is right to do and yet does not do it, he commits a sin.

The man who has knowledge of how to do good and does not do it, to him it is sin.

Therefore, he who knows that he ought to do a good thing, and does not do it, for him it is a sin.

The person, then, who knows what is right but fails to do it – that is sin in them.

Qui ergo novit facere bonum, nec facit, peccati reus est.

Therefore to him that knoweth to do good, and doeth it not, to him it is sin - That is, he is guilty of sin if he does not do it. Cotton Mather adopted it as a principle of action, "that the ability to do good in any case imposes an obligation to do it." The proposition in the verse before us is of a general character, but probably the apostle meant that it should refer to the point specified in the previous verses - the forming of plans respecting the future. The particular meaning then would be, "that he who knows what sort of views he should take in regard to the future, and how he should form his plans in view of the uncertainty of life, and still does not do it, but goes on recklessly, forming his plans beastingly and confident of success, is guilty of sin against God." Still, the proposition will admit of a more general application. It is universally true that if a man knows what is right, and does not do it, he is guilty of sin.
If he understands what his duty is; if he has the means of doing good to others; if by his name, his influence, his wealth, he can promote a good cause; if he can, consistently with other duties, relieve the distressed, the poor, the prisoner, the oppressed; if he can send the gospel to other lands, or can wipe away the tear of the mourner; if he has talents by which he can lift a voice that shall be heard in favor of temperance, chastity, liberty, and religion, he is under obligations to do it: and if, by indolence, or avarice, or selfishness, or the dread of the loss of popularity, he does not do it, he is guilty of sin before God. No man can be released from the obligation to do good in this world to the extent of his ability; no one should desire to be. The highest privilege conferred on a mortal, besides that of securing the salvation of his own soul, is that of doing good to others - of alleviating sorrow, instructing ignorance, raising up the bowed down, comforting those that mourn, delivering the wronged and the oppressed, supplying the wants of the needy guiding inquirers into the way of truth, and sending liberty, knowledge, and salvation around the world. If a man does not do this when he has the means, he sins against his own soul, against humanity, and against his Maker; if he does it cheerfully and to the extent of his means, it likens him more than anything else to God.

To him that knoweth to do good - As if he had said: After this warning none of you can plead ignorance; if, therefore, any of you shall be found to act their ungodly part, not acknowledging the Divine providence, the uncertainty of life, and the necessity of standing every moment prepared to meet God - as you will have the greater sin, you will infallibly get the greater punishment. This may be applied to all who know better than they act. He who does not the Master's will because he does not know it, will be beaten with few stripes; but he who knows it and does not do it, shall be beaten with many; Luke 12:47, Luke 12:48. St. James may have the Christians in view who were converted from Judaism to Christianity. They had much more light and religious knowledge than the Jews had; and God would require a proportionable improvement from them.
1. Saady, a celebrated Persian poet, in his Gulistan, gives us a remarkable example of this going from city to city to buy and sell, and get gain. "I knew," says he, "a merchant who used to travel with a hundred camels laden with merchandise, and who had forty slaves in his employ. This person took me one day to his warehouse, and entertained me a long time with conversation good for nothing. 'I have,' said he, 'such a partner in Turquestan; such and such property in India; a bond for so much cash in such a province; a security for such another sum.' Then, changing the subject, he said, 'I purpose to go and settle at Alexandria, because the air of that city is salubrious.' Correcting himself, he said, 'No, I will not go to Alexandria; the African sea (the Mediterranean) is too dangerous. But I will make another voyage; and after that I will retire into some quiet corner of the world, and give up a mercantile life.' I asked him (says Saady) what voyage he intended to make. He answered, 'I intend to take brimstone to Persia and China, where I am informed it brings a good price; from China I shall take porcelain to Greece; from Greece I shall take gold tissue to India; from India I shall carry steel to Haleb (Aleppo); from Haleb I shall carry glass to Yemen (Arabia Felix); and from Yemen I shall carry printed goods to Persia. When this is accomplished I shall bid farewell to the mercantile life, which requires so many troublesome journeys, and spend the rest of my life in a shop.' He said so much on this subject, till at last he wearied himself with talking; then turning to me he said, 'I entreat thee, Saady, to relate to me something of what thou hast seen and heard in thy travels.' I answered, Hast thou never heard what a traveler said, who fell from his camel in the desert of Joor? Two things only can fill the eye of a covetous man - contentment, or the earth that is cast on him when laid in his grave."
This is an instructive story, and is taken from real life. In this very way, to those same places and with the above specified goods, trade is carried on to this day in the Levant. And often the same person takes all these journeys, and even more. We learn also from it that a covetous man is restless and unhappy, and that to avarice there are no bounds. This account properly illustrates that to which St. James refers: To-day or to-morrow we will go into such a city, and continue there a year, and buy and sell, and get gain.
2. Providence is God's government of the world; he who properly trusts in Divine providence trusts in God; and he who expects God's direction and help must walk uprightly before him; for it is absurd to expect God to be our friend if we continue to be his enemy.
3. That man walks most safely who has the least confidence in himself. True magnanimity keeps God continually in view. He appoints it its work, and furnishes discretion and power; and its chief excellence consists in being a resolute worker together with him. Pride ever sinks where humility swims; for that man who abases himself God will exalt. To know that we are dependent creatures is well; to feel it, and to act suitably, is still better.

(9) Therefore to him that knoweth to do good, and doeth [it] not, to him it is sin.
(9) The conclusion of all the former treatise. The knowledge of the will of God does not only not at all profit, unless the life be answerable unto it, but also makes the sins far more grievous.

Therefore to him that knoweth to do good,.... This may regard not only the last particular of referring all things to the will of God, the sovereign disposer of life, and all events, which some might have the knowledge of in theory, though they did not practise according to it; but all the good things the apostle had exhorted to, and the contrary to which he had warned from, in this epistle; and suggests, that a Gnostic, or one that knows the will of God, in the several branches of it, revealed in his word,
and doth it not, to him it is sin: it is a greater sin; it is an aggravated one; it is criminal in him that is ignorant of what is good, and does that which is evil, nor shall he escape punishment; but it is much more wicked in a man that knows what is right and good, and ought to be done, and does it not, but that which is evil, and his condemnation will be greater; see Luke 12:47. The omission of a known duty, as well as the commission of a known sin, is criminal.

The general principle illustrated by the particular example just discussed is here stated: knowledge without practice is imputed to a man as great and presumptuous sin. James reverts to the principle with which he started. Nothing more injures the soul than wasted impressions. Feelings exhaust themselves and evaporate, if not embodied in practice. As we will not act except we feel, so if we will not act out our feelings, we shall soon cease to feel.

Therefore to him that knoweth to do good and doeth it not - That knows what is right, and does not practise it. To him it is sin - This knowledge does not prevent, but increase, his condemnation.