What does Galatians 1:7 mean?

Most of Paul's letters begin with some form of praise for his readers or, at the very least, thanks and praise to God for his readers. He skips right over that in Galatians. Instead, he has launched into the reason for his letter. He has said that he is astonished at how quickly his readers are deserting Jesus by turning to another gospel.

Now he quickly clarifies what he meant by using the phrase "a different gospel." In short, there is no other gospel! There is no other version of the truth that salvation comes through faith alone in Christ alone by God's grace alone. That's the only way sinners can be forgiven and become right with God. To change that message in any way is to "distort the gospel of Christ." Paul leaves no room here for the idea that some may believe one thing about salvation, while others believe differently, and yet all find their way to God.

Where did this other, distorted gospel come from? The Galatians had believed the truth when Paul and Barnabas were with them (Acts 13:43; 13:48-49). Paul points to "some who trouble you." These were called the Judaizers. They opposed Paul's teaching that Gentiles—those who were not Jewish—could be saved by grace, and so the Judaizers undermined his teaching. These men told new Gentile Christians that they were required to follow the law of Moses in order to be truly saved. Paul will have strong words for them in the book of Galatians.