20 Use your heads! Do you suppose for a minute that you can cut faith and works in two and not end up with a corpse on your hands? 21 Wasn't our ancestor Abraham "made right with God by works" when he placed his son Isaac on the sacrificial altar? 22 Isn't it obvious that faith and works are yoked partners, that faith expresses itself in works? That the works are "works of faith"? 23 The full meaning of "believe" in the Scripture sentence, "Abraham believed God and was set right with God," includes his action. It's that mesh of believing and acting that got Abraham named "God's friend." 24 Is it not evident that a person is made right with God not by a barren faith but by faith fruitful in works?
Matthew Henry's Commentary on James 2:20-24
Commentary on James 2:14-26
(Read James 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, verse 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.