The apostle having reproved the Galatians for not obeying the truth, and endeavoured to impress them with a sense of their folly herein, in these verses he largely proves the doctrine which he had reproved them for rejecting, namely, that of justification by faith without the works of the law. This he does several ways.

I. From the example of Abraham’s justification. This argument the apostle uses, Rom. 4:1-25. Abraham believed God, and that was accounted to him for righteousness (Gal. 3:6); that is, his faith fastened upon the word and promise of God, and upon his believing he was owned and accepted of God as a righteous man: as on this account he is represented as the father of the faithful, so the apostle would have us to know that those who are of faith are the children of Abraham (Gal. 3:7), not according to the flesh, but according to the promise; and, consequently, that they are justified in the same way that he was. Abraham was justified by faith, and so are they. To confirm this, the apostle acquaints us that the promise made to Abraham (Gen. 12:3), In thee shall all nations be blessed, had a reference hereunto, Gal. 3:8. The scripture is said to foresee, because he that indited the scripture did foresee, that God would justify the heathen world in the way of faith; and therefore in Abraham, that is, in the seed of Abraham, which is Christ, not the Jews only, but the Gentiles also, should be blessed; not only blessed in the seed of Abraham, but blessed as Abraham was, being justified as he was. This the apostle calls preaching the gospel to Abraham; and thence infers (Gal. 3:9) that those who are of faith, that is, true believers, of what nation soever they are, are blessed with faithful Abraham. They are blessed with Abraham the father of the faithful, by the promise made to him, and therefore by faith as he was. It was through faith in the promise of God that he was blessed, and it is only in the same way that others obtain this privilege.

II. He shows that we cannot be justified but by faith fastening on the gospel, because the law condemns us. If we put ourselves upon trial in that court, and stand to the sentence of it, we are certainly cast, and lost, and undone; for as many as are of the works of the law are under the curse, as many as depend upon the merit of their own works as their righteousness, as plead not guilty, and insist upon their own justification, the cause will certainly go against them; for it is written, Cursed is every one that continueth not in all things which are written in the book of the law, to do them, Gal. 3:10; Deut. 27:26. The condition of life, by the law, is perfect, personal, and perpetual, obedience; the language of it is, Do this and live; or, as Gal. 3:12; The man that doeth them shall live in them: and for every failure herein the law denounces a curse. Unless our obedience be universal, continuing in all things that are written in the book of the law, and unless it be perpetual too (if in any instance at any time we fail and come short), we fall under the curse of the law. The curse is wrath revealed, and ruin threatened: it is a separation unto all evil, and this is in full force, power, and virtue, against all sinners, and therefore against all men; for all have sinned and become guilty before God: and if, as transgressors of the law, we are under the curse of it, it must be a vain thing to look for justification by it. But, though this is not to be expected from the law, yet the apostle afterwards acquaints us that there is a way open to our escaping this curse, and regaining the favour of God, namely, through faith in Christ, who (as he says, Gal. 3:13) hath redeemed us from the curse of the law, etc. A strange method it was which Christ took to redeem us from the curse of the law; it was by his being himself made a curse for us. Being made sin for us, he was made a curse for us; not separated from God, but laid for the present under that infamous token of the divine displeasure upon which the law of Moses had put a particular brand, Deut. 21:22. The design of this was that the blessing of Abraham might come on the Gentiles through Jesus Christ—that all who believed on Christ, whether Jews or Gentiles, might become heirs of Abraham’s blessing, and particularly of that great promise of the Spirit, which was peculiarly reserved for the times of the gospel. Hence it appeared that it was not by putting themselves under the law, but by faith in Christ, that they become the people of God and heirs of the promise. Here note, 1. The misery which as sinners we are sunk into—we are under the curse and condemnation of the law. 2. The love and grace of our Lord Jesus Christ towards us—he has submitted to be made a curse for us, that he might redeem us from the curse of the law. 3. The happy prospect which we now have through him, not only of escaping the curse, but of inheriting the blessing. And, 4. That it is only through faith in him that we can hope to obtain this favour.

III. To prove that justification is by faith, and not by the works of the law, the apostle alleges the express testimony of the Old Testament, Gal. 3:11. The place referred to is Hab. 2:4; where it is said, The just shall live by faith; it is again quoted, Rom. 1:17; Heb. 10:38. The design of it is to show that those only are just or righteous who do truly live, who are freed from death and wrath, and restored into a state of life in the favour of God; and that it is only through faith that persons become righteous, and as such obtain this life and happiness—that they are accepted of God, and enabled to live to him now, and are entitled to an eternal life in the enjoyment of him hereafter. Hence the apostle says, It is evident that no man is justified by the law in the sight of God. Whatever he may be in the account of others, yet he is not so in the sight of God; for the law is not of faith—that says nothing concerning faith in the business of justification, nor does it give life to those who believe; but the language of it is, The man that doeth them shall live in them, as Lev. 18:5. It requires perfect obedience as the condition of life, and therefore now can by no means be the rule of our justification. This argument of the apostle’s may give us occasion to remark that justification by faith is no new doctrine, but what was established and taught in the church of God long before the times of the gospel. Yea, it is the only way wherein any sinners ever were, or can be, justified.

IV. To this purpose the apostle urges the stability of the covenant which God made with Abraham, which was not vacated nor disannulled by the giving of the law to Moses, Gal. 3:15 Faith had the precedence of the law, for Abraham was justified by faith. It was a promise that he built upon, and promises are the proper objects of faith. God entered into covenant with Abraham (Gal. 3:8), and this covenant was firm and steady; even men’s covenants are so, and therefore much more his. When a deed is executed, or articles of agreement are sealed, both parties are bound, and it is too late then to settle things otherwise; and therefore it is not to be supposed that by the subsequent law the covenant of God should be vacated. The original word diatheke signifies both a covenant and a testament. Now the promise made to Abraham was rather a testament than a covenant. When a testament has become of force by the death of the testator, it is not capable of being altered; and therefore, the promise that was given to Abraham being of the nature of a testament, it remains firm and unalterable. But, if it should be said that a grant or testament may be defeated for want of persons to claim the benefit of it (Gal. 3:16), he shows that there is no danger of that in this case. Abraham is dead, and the prophets are dead, but the covenant is made with Abraham and his seed. And he gives us a very surprising exposition of this. We should have thought it had been meant only of the people of the Jews. “Nay,” says the apostle, “it is in the singular number, and points at a single person—that seed is Christ,” So that the covenant is still in force; for Christ abideth for ever in his person, and in his spiritual seed, who are his by faith. And if it be objected that the law which was given by Moses did disannul this covenant, because that insisted so much upon works, and there was so little in it of faith or of the promised Messiah, he answers that the subsequent law could not disannul the previous covenant or promise (Gal. 3:18): If the inheritance be of the law, it is no more of promise; but, says he, God gave it to Abraham by promise, and therefore it would be inconsistent with his holiness, wisdom, and faithfulness, by any subsequent act to set aside the promise, and so alter the way of justification which he had thus established. If the inheritance was given to Abraham by promise, and thereby entailed upon his spiritual seed, we may be sure that God would not retract that promise; for he is not a man that he should repent.