{11} But wilt thou know, O vain man, that faith without works is dead?

(11) The third reason from the example of Abraham, who no doubt had a true faith: but he in offering his son, showed himself to have that faith which was not without works, and therefore he received a true testimony when it was laid, that faith was imputed to him for righteousness.

People's New Testament

2:20 But wilt thou know, O vain man. I will show by proof that the faith that justifies produces works by the case of Abraham, the great father of the faithful.

Faith without works is dead. It has no power to make alive unless it has power over the life.

Wesley's Notes

2:20 But art than willing to know - Indeed thou art not: thou wouldest fain be ignorant of it. O empty man - Empty of all goodness. That the faith which is without works is dead - And so is not properly faith, as a dead carcase is not a man.

Jamieson-Fausset-Brown Bible Commentary

20. wilt thou know-"Vain" men are not willing to know, since they have no wish to "do" the will of God. James beseeches such a one to lay aside his perverse unwillingness to know what is palpable to all who are willing to do.

vain-who deceivest thyself with a delusive hope, resting on an unreal faith.

without works-The Greek, implies separate from the works [Alford] which ought to flow from it if it were real.

is dead-Some of the best manuscripts read, "is idle," that is, unavailing to effect what you hope, namely, to save you.

Matthew Henry's Concise Commentary

2:14-26 Those are wrong who put a mere notional belief of the gospel for the whole of evangelical religion, as many now do. No doubt, true faith alone, whereby men have part in Christ's righteousness, atonement, and grace, saves their souls; but it produces holy fruits, and is shown to be real by its effect on their works; while mere assent to any form of doctrine, or mere historical belief of any facts, wholly differs from this saving faith. A bare profession may gain the good opinion of pious people; and it may procure, in some cases, worldly good things; but what profit will it be, for any to gain the whole world, and to lose their souls? Can this faith save him? All things should be accounted profitable or unprofitable to us, as they tend to forward or hinder the salvation of our souls. This place of Scripture plainly shows that an opinion, or assent to the gospel, without works, is not faith. There is no way to show we really believe in Christ, but by being diligent in good works, from gospel motives, and for gospel purposes. Men may boast to others, and be conceited of that which they really have not. There is not only to be assent in faith, but consent; not only an assent to the truth of the word, but a consent to take Christ. True believing is not an act of the understanding only, but a work of the whole heart. That a justifying faith cannot be without works, is shown from two examples, Abraham and Rahab. Abraham believed God, and it was reckoned unto him for righteousness. Faith, producing such works, advanced him to peculiar favours. We see then, ver. 24, how that by works a man is justified, not by a bare opinion or profession, or believing without obeying; but by having such faith as produces good works. And to have to deny his own reason, affections, and interests, is an action fit to try a believer. Observe here, the wonderful power of faith in changing sinners. Rahab's conduct proved her faith to be living, or having power; it showed that she believed with her heart, not merely by an assent of the understanding. Let us then take heed, for the best works, without faith, are dead; they want root and principle. By faith any thing we do is really good; as done in obedience to God, and aiming at his acceptance: the root is as though it were dead, when there is no fruit. Faith is the root, good works are the fruits; and we must see to it that we have both. This is the grace of God wherein we stand, and we should stand to it. There is no middle state. Every one must either live God's friend, or God's enemy. Living to God, as it is the consequence of faith, which justifies and will save, obliges us to do nothing against him, but every thing for him and to him.