15 Brothers, as men would say, even a man's agreement, when it has been made certain, may not be put on one side, or have additions made to it. 16 Now to Abraham were the undertakings given, and to his seed. He says not, And to seeds, as of a great number; but as of one, he says, And to your seed, which is Christ. 17 Now this I say: The law, which came four hundred and thirty years after, does not put an end to the agreement made before by God, so as to make the undertaking without effect. 18 Because if the heritage is by the law, it is no longer dependent on the word of God; but God gave it to Abraham by his word.
19 What then is the law? It was an addition made because of sin, till the coming of the seed to whom the undertaking had been given; and it was ordered through angels by the hand of a go-between. 20 Now a go-between is not a go-between of one; but God is one. 21 Is the law then against the words of God? in no way; because if there had been a law which was able to give life, truly righteousness would have been by the law. 22 However, the holy Writings have put all things under sin, so that that for which God gave the undertaking, based on faith in Jesus Christ, might be given to those who have such faith.
Matthew Henry's Commentary on Galatians 3:15-22
Commentary on Galatians 3:15-18
(Read Galatians 3:15-18)
The covenant God made with Abraham, was not done away by the giving the law to Moses. The covenant was made with Abraham and his Seed. It is still in force; Christ abideth for ever in his person, and his spiritual seed, who are his by faith. By this we learn the difference between the promises of the law and those of the gospel. The promises of the law are made to the person of every man; the promises of the gospel are first made to Christ, then by him to those who are by faith ingrafted into Christ. Rightly to divide the word of truth, a great difference must be put between the promise and the law, as to the inward affections, and the whole practice of life. When the promise is mingled with the law, it is made nothing but the law. Let Christ be always before our eyes, as a sure argument for the defence of faith, against dependence on human righteousness.
Commentary on Galatians 3:19-22
(Read Galatians 3:19-22)
If that promise was enough for salvation, wherefore then serveth the law? The Israelites, though chosen to be God's peculiar people, were sinners as well as others. The law was not intended to discover a way of justification, different from that made known by the promise, but to lead men to see their need of the promise, by showing the sinfulness of sin, and to point to Christ, through whom alone they could be pardoned and justified. The promise was given by God himself; the law was given by the ministry of angels, and the hand of a mediator, even Moses. Hence the law could not be designed to set aside the promise. A mediator, as the very term signifies, is a friend that comes between two parties, and is not to act merely with and for one of them. The great design of the law was, that the promise by faith of Jesus Christ, might be given to those that believe; that, being convinced of their guilt, and the insufficiency of the law to effect a righteousness for them, they might be persuaded to believe on Christ, and so obtain the benefit of the promise. And it is not possible that the holy, just, and good law of God, the standard of duty to all, should be contrary to the gospel of Christ. It tends every way to promote it.