Paul asks what moved them to leave the faith and hang upon the law, 1-5. Those who believe are justified, 6-8, and blessed with Abraham, 9. And this he shows by many reasons, 10-29.
1 O foolish Galatians, who has bewitched you, that you should not obey the truth, before whose eyes Jesus Christ has been evidently set forth, crucified among you? 2 I only wish to learn this from you: did you receive the Spirit by the works of the law, or by the hearing of faith? 3 Are you so foolish? Having begun in the Spirit, are you now made perfect by the flesh? 4 Have you suffered so many things in vain—if it is yet in vain? 5 He therefore who ministers to you the Spirit and works miracles among you, does he do this by the works of the law, or by the hearing of faith?
6 Even so "Abraham believed God, and it was accounted to him for righteousness." 7 Know therefore, that those who are of faith, the same are the children of Abraham. 8 And the Scripture, foreseeing that God would justify the heathen through faith, preached the gospel beforehand to Abraham, saying, "In you all nations shall be blessed." 9 So then those who are of faith are blessed with faithful Abraham.
10 For as many as are of the works of the law are under the curse, for it is written, "Accursed is everyone who does not continue in all things which are written in the book of the law to do them." 11 Now it is evident that no man is justified by the law in the sight of God, for, "The just shall live by faith." 12 And the law is not of faith, but, "The man who does them shall live by them." 13 Christ has redeemed us from the curse of the law, being made a curse for us, for it is written, "Accursed is everyone who hangs on a tree," 14 So that the blessing of Abraham might come on the Gentiles through Jesus Christ so that we might receive the promise of the Spirit through faith.
15 Brothers, I speak after the manner of men. Though it is but a man's covenant, yet if it is confirmed, no man makes it void or adds to it. 16 Now the promises were made to Abraham and his seed. He does not say, "And to seeds," as of many, but as of one, "And to your seed," which is Christ. 17 And I say this: that the covenant that was confirmed before by God in Christ, the law, which was four hundred and thirty years after, cannot invalidate so that it should make the promise of no effect. 18 For if the inheritance is by the law, it is no longer by promise. But God gave it to Abraham by promise.
19 What purpose then does the law serve? It was added because of transgressions until the seed should come to whom the promise was made. And it was ordained by angels in the hand of a mediator. 20 Now a mediator is not a mediator of one, but God is one. 21 Is the law then against the promises of God? By no means. For if there had been a law given which could give life, truly righteousness would have been by the law. 22 But the Scripture has enclosed all under sin so that the promise by faith of Jesus Christ might be given to those who believe.
23 But before faith came, we were kept under the law, shut up to the faith which should afterward be revealed. 24 Therefore, the law was our school-master to bring us to Christ so that we might be justified by faith. 25 But after faith has come, we are no longer under a school-master. 26 For you are all children of God by faith in Christ Jesus. 27 For as many of you as have been baptized into Christ, have put on Christ. 28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female, for you are all one in Christ Jesus. 29 And if you are Christ's, then you are Abraham's seed and heirs according to the promise.
Matthew Henry Commentary - Galatians, Chapter 3[➚]
[v.6] - Quoting Genesis 15:6 (LXX).
[v.8] - Quoting Genesis 12:3 (LXX—paraphrased). See also, Genesis 18:18, 22:18, 26:4.
[v.10] - Quoting Deuteronomy 27:26 (LXX—paraphrased).
[v.11] - Quoting Habakkuk 2:4 (LXX).
[v.12] - Quoting Leviticus 18:5 (LXX).
[v.13a] - "being made a curse for us" - Reference, 2nd Corinthians 5:21.
[v.13b] - Quoting Deuteronomy 21:23.
[v.16] - Quoting Genesis 17:7-8 (LXX).
[v.17] - "four hundred and thirty years" - Reference, Genesis 15:13; Exodus 12:40; Acts 7:6.
[v.22] - "enclosed all under sin" - Reference, Psalm 14:1, 53:1; Ecclesiastes 7:20; Romans 3:10, 19, 23.
[v.24-25] - "school-master" - This is a male teacher at a school. However, this word is not a great translation from the Greek word, παιδαγωγους, paidagogos (pahee-dag-o-gos'), which literally means, boy leader. These were slaves whose job was to lead boys to school. There really is no good English word to use for this word, whether it be instructor, teacher, guide, or tutor. So, knowing the meaning behind the Greek word, we can see that the law is tasked with being our leader to Christ. But in faith, we are under Christ as our leader and the law's task no longer applies to us. In other words, we are no longer under the leadership, or direction, of the law, but under that of Christ our Lord and Savior.