1-2: Paul's introduction includes his credentials as an apostle divinely appointed by God.
3-5: He greeted the confused church with a reminder of the Gospel. It was God's will to send Jesus as a sacrifice for our sins so we could be delivered from the present evil age. God deserves glory throughout all eternity.
6-9: Paul diagnosed the church's problem in Galatia: they distorted the Gospel into a legalistic system that leads to condemnation.
10: He's probably responding to accusations of being a "people pleaser". This letter is proof that he cared more about God's approval than his peers. Paul saw a dichotomy between pleasing God and seeking to please man.
11-24: Paul was a zealous Pharisee that persecuted Christians. He received a direct revelation from Jesus and became a Christian and apostle before meeting with the other apostles. His purpose in telling them was to counter their challenges to his authority as an apostle.
1-10: Paul presented the Gospel and his testimony to the church leaders in Jerusalem. Peter and John recognized his authority as an apostle.
11-14: Peter feared the rejection of a group of Jewish "Christians" called "the circumcision party" and distanced himself from the uncircumcised Gentiles whom he regularly ate with. Paul confronted Peter's hypocrisy in front of everyone.
15-16: No one, including Jews, can be justified by works of the law. We are all guilty of sin and no amount of future obedience to the law can change that.
17-18: When a professing Christian regresses into sin by disobeying God's law it does nothing to discredit Christ. Our failure to obey only proves we are transgressors who need God's grace.
19-20: Breaking God's law causes spiritual death. The only way to avoid judgment after death is to be "Crucified with Christ". This means giving up our sinful desires and identifying with Jesus through faith; faith that His death on the cross fully satisfied the wrath of the Father. When we die to ourselves and receive Christ, the Holy Spirit's desires become our desires.
21: Our sin cannot make God's grace invalid. If there were a way to enter heaven by good works then Jesus' payment for our sins would be unnecessary. Had there been another way, the Father would have granted Jesus' request to let the cup of His wrath pass.
1-9: The Christians in Galatia reverted back to the false belief that you can earn salvation through obedience to the law. Paul corrected their thinking through a series of rhetorical questions along with the statement that we are justified by faith rather than works of the law. Faith is the act of trusting in Jesus' payment for our sins. In order to trust in Him we must first agree we are guilty sinners and turn from our sin with an attitude that results in obedience.
10-14: All who rely on their good works for justification are cursed because they have broken the law. Christ redeemed us on the cross by substituting himself and becoming a "curse for us". We access His grace and forgiveness through faith: trusting in Jesus' sacrifice as full payment for our sins.
15-18: The law didn't nullify the Abrahamic covenant because the Abrahamic covenant was based on God's promise, unlike the conditional Mosaic covenant.
19-22: The purpose of the law is to make us aware of our transgressions and see our need for a savior. No intermediary was required because God was the only party involved in the Abrahamic covenant.
23-26: Before Jesus came and fulfilled the law, everyone stood condemned, destined to face punishment for their sins. If Jesus never came, the temple sacrifices would be powerless to atone for the sins of past believers and all of humanity would have to endure God's wrath. But now that Jesus fulfilled the law and died for our sins we are no longer prisoners under the law. This fulfillment validated the entire sacrificial system set in place for past believers.
27-29: Unity in Christ supersedes all racial, economic, and gender classes. No one is superior or inferior based on these differences. Our identity is in Christ. And if our identity is in Christ, we are Abrahams offspring and heirs according to the promise.
1-7: Prior to Jesus' atonement both Jews and gentiles were slaves to the law and religious rituals. But when Jesus came to redeem us we became sons and heirs through God.
8-11: Paul scolded the Galatians for returning to the "elementary principles" of observing religious rituals rather than resting in the finished work of Christ. Religious rituals are an attempt to make yourself righteous before God, but salvation through Jesus is God's provision of righteousness for man.
12-16: Paul wanted the Galatians to "become as he is" by trusting in Christ for righteousness rather than relying on religious rituals. He became like them by matching their sacrificial love for him, when he preached to them with an ailment that was burdensome. Perhaps it had something to do with his vision since they would have given him their eyes if they could. Though his rebuke is firm, verse 16 points out that he is not their enemy: he's simply telling the truth.
17-18: The legalistic group convinced them to obey rituals out of their own self interest and reputation.
19-20: Paul had an intimate relationship with the church in Galatia, one he compared to a mother and child. He was sensitive to the harsh tone his letter had and desired to speak to them gently in person.
21-31: Abraham's children with Sarah and Hagar can be interpreted allegorically as covenants. Those under the law are born of the slave woman and remain slaves to the law, while those born of the promise are sons of Sarah and are free from the condemnation of the law.
1-4: Jesus set us free from the obligation of the law. In order to access this freedom we must trust fully in Jesus, who payed our sin debt in full. Those who attempt to earn salvation through the law (through circumcision, sacrifices, obeying commandments, etc.) disqualify themselves from Jesus' grace. They are obligated to keep the whole law or face judgement.
5-6: The sign of circumcision was given to Israel as a physical symbol of a cleansed heart (Deuteronomy 30:6) and a reminder of God's promise to Abraham. Jesus' death and resurrection was the fulfillment of the two things circumcision symbolized: A clean heart and the seed that blessed the nations, which he did by providing salvation for all who believe. That is why circumcision means nothing anymore: it was simply a temporary sign until the fulfillment came.
7-12: The Christians in Galatia were doing well in their theology until false teachers came and preached salvation through circumcision. Just as leaven affects the entire lump of dough, false teachers affected the entire church. However, Paul was confident that the Christians in Galatia would correct their theology after reading this letter.
13-15: Christians are called to be free from the law's regulations and condemnation. But this does not mean we are free to disobey God's moral law. Because God loved us and paid a great price to save us, we should obey the law by loving our neighbor.
16-26: To "walk in the Spirit" probably means to live humbly in obedience to God's word while seeking and acknowledging the Holy Spirit's guidance in our life. The Spirit convicts us when given the choice to sin. If we obey Him we are walking in the Spirit rather than gratifying our flesh (sinful desires). But our fleshly desires oppose the Spirit, causing us to sin (Romans 7). Paul gives a list of fleshly works and fruit of the Spirit so we can know which of the two we are walking in.
1-2: This command shows the graceful approach Christians must take in confronting a Christian brother about his sin. We approach them humbly and with caution, knowing we too are capable of falling into the same sin. We don't have an accusing attitude or condemn them. With these things in mind, we must seek to help them out of their sin.
6: This verse echoes the biblical teaching not to "muzzle the ox". A pastor who faithfully teaches the word should be supported by his congregation because they benefit spiritually from his teaching.
7-8: The principle of reaping and sowing also applies to our spiritual lives. The choice of living a godless, sinful life will bring about destruction, while those seeking to please the Holy Spirit will receive Christ and reap eternal life by God's grace.
9-10: If we endure in doing good towards others, especially to fellow believers, we will reap eternal rewards.
11-16: The hypocritical false teachers taught circumcision to avoid persecution by pleasing the religious rulers who crucified Jesus. While these teachers boasted in the flesh, Paul only boasted in Christ. Circumcision is irrelevant and obsolete in the New covenant. All that counts is becoming a new creation in Jesus through his death and resurrection.
17-18: Paul closes the letter and mentions that he has the "marks of Jesus", which is probably a reference to the whip marks on his back from being persecuted.