Galatians 3 begins a 3-chapter series of rebukes and illustrations designed to show the inferiority and invalidity of the Law of Moses. It confirms and continues Paul’s teaching about the danger of the Judaizing teachers who wanted to “pervert the gospel of Christ” (1:7), his refusal to give in to the Judaizers (2:3-5), and his public rebuke of Peter’s hypocrisy concerning the Gentiles (2:11-16).
In a marvelous use of rhetoric, Paul exposes the Galatians’ lack of discernment (vv 2-5). In a stinging conclusion, Paul declares that only those who are of faith (as opposed to the Law) are the sons of righteous Abraham (vv 6-9).
In verse 10, Paul moves from a practical line of argumentation to a theological one: “For as many as are of the works of the Law are under a curse; for it is written, ‘Cursed is everyone who does not continue in all things which are written in the book of the Law, to do them’” (v 10). The good news, says Paul, is that Jesus became a curse for all men, that all men, both Jew and Gentile, might be delivered from the curse of the Law (vv 13-14).
To further build his case, Paul again goes back beyond the Law to show that God’s promise to Abraham included all men, both Jew and Gentile. Moreover, the Law, coming 430 years after the promise, could not annul the promise. Thus, the promise was far greater than the curse.
Lest anyone misunderstand Paul’s attitude toward the Law (cf Rom 3:1-2), Paul shows the usefulness of the Law to bring to men the knowledge of sin while also bring men to an appreciation for the gift of Christ (vv 19-25).
I would be remiss if I failed to mention Galatians 3:26-29. First, Galatians 3:26 does not teach salvation by faith only. Verse 27 begins with “For,” meaning it is an explanation of the previous text. Thus, those who have been baptized into Christ are the sons of God by faith.
Second, Galatians 3:28 is not a dissolution of gender differences in the work and worship of the church. Being one in Christ via baptism does not negate what Paul said elsewhere about gender roles in the church (cf 1 Cor 14:34; 1 Tim 2:8-15).
Finally, only those who in Christ are heirs of the promise to Abraham (salvation through Jesus). The only way to be in Christ is to be baptized into Christ (v 27).