What does Galatians 4:12 mean?

Paul has been encouraging Christians to accept that they have already been fully made right before God—"justified"—by faith in Christ's death for their sins. To begin to follow the law of Moses, in hopes of being justified, simply makes no sense. Worse, it would make them slaves to their sin again. To depend on rituals and sacraments for salvation means asking God to judge them based on their works instead of Christ's work on the cross.

Now, Paul calls them these Galatians "brothers." This demonstrates that he believes what he has written earlier. In Christ, they are all one. He is not superior to them because he is Jewish, or Roman, or male, or free and not a slave (Galatians 3:28). In fact, he begs them to become as he is because he has become as they are.

In other words, Paul is asking the Galatian Christian to fully accept their status as free men and women in Christ as he, Paul, has fully abandoned his own status as a man "under the law" to live free in Christ himself.

In the following verses, Paul continues a new thought, insisting that the Galatians did no wrong to him when he was with them.