**Taken from the Crossway ESV Study Bible
Verses 6-9 Paul warns the church of Galatia against the gospel that was being taught to them that wasn't the gospel Paul had originally preached to them. Paul assures them that the gospel he preaches is the true gospel, and that he is a trustworthy vessel of God's Word. One example of the "different gospel" mentioned in verses 6-9 refers to the Old Testament teaching of Moses, where you need to be circumcised and follow the Mosaic Law in order to be a follower of God. Basically, they were taught that they needed to become Jewish in order to be saved. In Acts 10, Peter had a vision of a net coming down from heaven containing animals, reptiles and birds that the Jews were "unclean" and not supposed to eat; such as ravens, lizards, hawks, pigs, etc. God spoke to Peter and told him to eat what was in the net. Peter refused three times. Peter was confused by this vision, as he was Jewish and by the law, he was not allowed to eat the things in the net from the vision. Why was God asking him to disobey the Jewish law? Just after the vision, Peter was told that men would come to his door and that he needed to go with them. Minutes later, men came to his door, and he went with them. These men were Gentiles, and it was unlawful for the Jews to associate with such people. Peter realized that the vision he had of the "unclean animals" in the net was not a literal expression of God not eat the animals in the net, but rather, God asking him to associate with people he was taught were "unclean". When Peter was with these people, God showed him that they too, were accepted by God- which was completely against the Jewish teaching. So, although Paul was taught through his religion that only Jews were saved and followers of God, his knowledge of that changed, when God revealed to him that the Gentiles could also attain eternal life through repentance and should not be judged because they don't follow Jewish law, but rather the Jewish law was void because Christ introduced a new covenant that replaced the Mosaic Law. Jesus was the only way to heaven- not by following traditions and rules made by men of the Old Testament. Paul was chosen by God, to preach Christ to the Gentiles and kings and the children of Israel. (Acts 9)
Paul repeated twice that if anyone is preaching a gospel other than that he taught (the truth) let that man be accursed. We really need to test ALL that we hear about God, Jesus and the Scriptures. If it, in any way, is different, contrary, distorted from what the Bible says, it is not the true gospel. Remember in 2 Corinthians chapter 11, we just read about false prophets. Many prophets are deceived themselves, and so lead others astray. This was Paul's major concern with the Galatians- that they would not be led astray but would stay firm in the gospel that was preached to them by himself. Note in verses 11 and 12 where Paul says that he did not learn about Jesus from man or was taught by another apostle, but was given revelation by God himself. (Acts 9) Paul's conversion was quite significant as he tried to destroy the church- persecuting and killing people who followed Christ. Paul was so well known as the persecutor, when he became saved, many were unsure if he was the real deal. Because of his enormous transformation in Christ, people glorified God because of his testimony They only were hearing it said, "He who used to persecute us is now preaching the faith he once tried to destroy." And they glorified God because of me. ~Verse 23-24.
Paul also asked the Galatians, am I trying to please man or God? This is a question I want you to ask yourself. Are you seeking the approval of man or of God? You can't seek both. If you are a true follower of Jesus, you should only be seeking God's approval, as Paul answered. In what ways do you struggle with trying to please people? Let us not do so, but only seek God and His approval, for He has the only opinion that counts.
Lord, I pray that our eyes would be open to the truths of Your Word. I ask that we would have discernment about doctrine that is contrary to that which is Yours. May we aim to please You, and You alone. Show us areas in our lives that we try to please people, so that we can rid ourselves of that ungodliness. Amen.
For am I now seeking the approval of man, or of God? Or am I trying to please man? If I were still trying to please man, I would not be a servant of Christ.