What does Galatians 1:1 mean?

Galatians is one of Paul's earliest letters, also known as "epistles." It was the custom of the times to begin a letter by identifying oneself. Paul always follows that pattern, but he does so here much more abruptly. He immediately describes himself as an apostle. In Greek, the word apostle means someone who is sent to accomplish a specific purpose. In the New Testament, the word is mostly used of the 12 men Jesus called and trained during His ministry on earth and then commissioned to represent Him in the world.

Paul was called by Jesus to be an apostle after the resurrection (Acts 9:3–9). In Galatians 1, he describes in some detail how and when Christ trained and sent him out to preach the gospel of Jesus.

Paul is writing Galatians to confront the lies being told to Christians about the truth of Jesus' gospel. In order to attack the true message of Jesus—the one Paul has been preaching and people have been believing—those men have been attacking Paul's credentials. He's not one of the 12, after all. Is he really an apostle or is he just teaching his own version of Christ's message?

So Paul begins his letter by stating outright that he is, in fact, a genuine apostle. He wasn't given the title by any human person. His position comes straight from Jesus Christ and God the Father, "who raised [Jesus] from the dead." Paul will insist that he was trained and sent out by the resurrected Son of God, giving him all the authority he needs to declare what it means to be saved by grace through faith in Christ.