Overview
Many consider this the first part of the New Testament ever written, predating the gospels by a few years. There is some dispute over this, but at least can be considered the earliest writing of Paul. Unlike other letters, this is addressed to a group of churches in Galatia instead of an indvidual church. Another striking difference in this letter is the fact that he begins to address a central issue just after the greeting.

Paul appears to be defending himself against some serious charges. He is accused of being a fraud (not a real apostle), a panderer (trying to please men), and a libertine. It seems that some ‘from James’ have come and are trying to persaude the Gentile belivers to obey the Mosaic Law. Based on Paul’s tone, it appears that many are ready to go along with Jewish teachers. Paul defends his apostleship vigourously and goes on the attack against those that would force circumcision (and the rest of the law) onto the Gentiles.

Chapter 1 – Who I Am
Paul starts in verse 6 with a direct attack against his accusers. He hints at it in verse 1, but begins here with a severe tone. He is shocked and dismayed that so many are giving into this teaching and goes on to show that this is not consistent with the gospel message he preached to them at first. He emphasizes that even if an angel says something different than his gospel, it is not from God.
Of course, this assertion begs the question, “Who do you think you are?” In short, he answers that he is called by Jesus himself to minister to the Gentiles. His teachings came from the source, not some filtered-down version of the truth. He goes on to talk about his life before and after meeting Jesus, then mentioned his first trip to Jerusalem three years after his conversion.
Paul talks about his past as a Pharisee, but not just an ordinary one. He was zealous for the traditions of his fathers. In short, if there was ever a Pharisee of Pharisees, it was him. Remember that he was taught by Rabbon Gamaliel, one of only four in all of Talmudic tradition to be called ‘Master’. He advanced beyond those of his age. Although he doesn’t state it here, he went out and sought authority to have Christians killed.
However, God had mercy on him and called him to the ministry to preach for the church he had spent so long chastizing. Note that he goes to some length to emphasize that his message is not from the other apostles in Jerusalem.
Speaking of the apostles in Jerusalem, he mentions his first meeting with Cephas to “get information from him”(New English Translation). This was not a social call as may be implied in some translations. The point is that his contact with the apostles was very limited. It was three years after his conversion before he made the trip. On the trip, he saw Cephas (Peter) and stayed with him for 15 days. Along the way, he may have seen James as well. Otherwise, there was no contact with them. He was unknown in Judea, but concludes that a good report was written about him.

Chapter 2 – Confirmed not Commanded by the Apostles
While mentioning his first trip to Jerusalem, he tells the story of his confirmation by the other apostles. This story is told in Acts 15:1 – 35. He mentions that he had begun defending the gospel against these false teachers before the trip. It seems these brothers went to “spy on” the freedom of Christ. However, for the sake of the Galatians and the gospel, he gave the detractors no quarter. In fact, the Greeks with Paul didn’t feel the need to be circumcised. The apostles and those that were ‘influential’ encouraged them in their message without adding anything to it. In fact, Paul mentioned that they urged him to remember the poor, a pillar of his ministry.
To continue with the defense of the gospel, he mentions an incident involving Cephas. Basically, although Cephas and the other apostles had confirmed his message, he gave in to peer pressure when these false teachers were around. Oddly enough, they even won over Barnabas even though he was not from Judea. Paul confronts him pubicly. Although he doesn’t provide Cephas’ response, it’s fair to imply that the rebuke was accepted. Much later, Cephas in 2 Peter characterizes Paul’s message as Scripture, certainly not a position held by someone still smarting for public embarassment.
After talking about the source of his message, Paul then begins to remind the Galatians of the fundamental truths of the gospel. At the core of the gospel, justification comes from faith in Jesus, not by obeying the Mosaic Law. In fact, the indwelling Spirit of God is the means to live out this righteousness. If these two things are not true, then Christ died for nothing.

Chapter 3 – Children of Promise
Paul begins his argument by reminding the Galatians of their salvation. Did you receive the Spirit from doing the works of the law? (New English Translation) He makes it plain that not only can a person be justified by the law, but that the Spirit of God comes through faith and not obedience to the Law.
For there, he begins to talk about Abraham. No doubt the Judiazers would point to Genesis 17:1 – 22 as prooftext. For that reason, he couldn’t start by talking about Jesus, or even about Moses. They had gone all the way back to the covenant of circumcision, so he had to begin with him.
Incidentally, some had accepted Jesus. As Gordon Fee says in Reading the Bible Book by Book, they would have said that a person must believe in Jesus and then be circumcized. For them it was a matter of identity. You could almost say the it was an “outward sign of an inward grace”.
Aside from that, Paul begins with the foundation of faith. Abraham’s faith was credited to him as righteousness. Those with faith are identified as sons of Abraham. He goes on to demonstrate the curse of the law and how Jesus became cursed for our sake on the cross. Yes, the law and circumcision came in Genesis 17, but Jesus fulfilled the law so that the original promise would still be true. In short, faith is what identifies us as children of Abraham, not circumcision.
Paul takes this argument further by demonstrating that being children of this promise makes of heirs of God. A legal contract cannot nullify the original promise. That still holds true. The Law came after the promise, so it cannot, by nature, go against that promise. The law does not make us children of Abraham, the promise of faith does.
Then the question comes, “Why did God create the Law in the first place and avoid all this confusion?”. It came to point the way to Jesus. Jesus was the literal heir to the promise, the descendant (singluar) mentioned in Gen 12. The law was administered to by angels through a representative. Moses was not a mediator, for example, who worked for compromise between opposing parties. He instead was God’s representative to his people who enabled them to have a relationship, but entirely on God’s terms. (Notes on Galatians, NET Bible). Without the law, Jesus could not have been the descendant spoken of in the original promise.

Chapter 4 – Pleas of a Concerned Father
Paul continues the argument that faith in Jesus makes us heirs. Since Jesus has come, we are no longer under the imprisonment of the law. Jesus, through faith, allows us to be sons of God through faith. Having been made sons of God, we have been made heirs through the glorious promise of God through Christ.
Having made the case for Christ, he begins to plea with the Galatians to not return to the imprisonment of the law. First, he says that the law is inferior, so there is no reason to return to it. It’s principles do not give life, not do they save you. Then he appeals to them personally. He asks them to think of how happy they were to receive the message in the first place. Finally, he uses a comparison between Ishmael and Issac to bring the point home. You can be a child of the law, like Ishmael, whose mother was a slave, or you can be a child of the promise, like Issac, whose mother was free. God had said that the two brothers would be in conflict, and the same is true today. However, those that are children of the law will not inherit the promise, only those born into it.

Chapter 5 – Freedom Presents a Choice
Paul leads into this chapter by comparing Ishmael and Issac, the law and the promise, the flesh and the Spirit. Being a child of the promise gives you complete freedom in Christ. If you obey one part of the law, you have to obey all of it. As it is, we have been saved through faith apart from the law. You can’t do enough to be righteous, the only thing that matters is faith expressing itself through love.
This freedom presents a choice, live by the Spirit or live by the flesh. Don’t abuse this freedom and live by the flesh. If you live by the flesh, the effects are obvious, lust, divisions, debauchery and the like. This way of life takes you away from God and ultimately will cost you the greatest promise of Heaven. If you live by the Spirit, then the effects are equally obvious, love, gentleness, patience, self-control and the like. Those who choose this way will listen to the Spirit and live according to his desires. (After all, we’re dead through the cross, we can’t live through our own desires!) Lastly, he pleas with them to not use their freedom to provoke each other. No one is better than another and we are all brothers through Christ.

Chapter 6 – Love One Another
As he said at the beginning of the letter, the prescene of sin doesn’t negate the benefit of Christ. To crash down on someone caught in sin is to miss the point. Restore the brother gently, but don’t be too gentle, otherwise you’ll fall into the temptation of doing to same thing.
Outside of dealing with sin and listening to the Spirit, we should take every opportunity to do good with each other. If you have a good word, share it with everyone. After all, if you feed the flesh, you’ll inherit destruction. If you feed the Spirit, you’ll inherit enternal life.
In a parting shot, he again makes the point that the issue is not circumcision or the lack of circumcision;the issue is being made new through our faith in Jesus. This is not a legal matter to be disputed, instead the freedom of Christ is what reigns in our lives so that we may do good to each other and to the world.