What does Galatians 4:15 mean?

Paul has been reminding the Galatians of how they first came to know each other. He was sick, and that illness somehow became the reason for his opportunity to tell them about Jesus (Galatians 4:13–14). Paul's "bodily ailment" could have given them reason to reject him and his message. He called his illness a trial to them. Instead of scorning Paul, however, the Galatians honored him. They received him and his message about Jesus as if he were an angel or even Jesus Christ Himself. It was a remarkable response.

Now Paul asks them what happened: "What became of your blessedness?" He wants to know what changed between their first season together, and this moment in which they are rejecting the gospel Paul preached, the truth of God's grace through faith in Jesus. Why would they go from receiving Paul's message of Christ with such joy, to disbelieving and beginning to volunteer as slaves under the law of Moses?

Back then, Paul remembered, they would have gouged out their eyes and given them to him. That's a perplexing comment, given that we don't know the full context of what happened between these believers and Paul. Scholars suggest that perhaps Paul's illness had to do with his eyes. Maybe he is suggesting that, if eye transplants were possible, the Galatians would have willingly given him theirs. Or perhaps Paul is simply using extreme language to describe how incredibly loyal and committed the Galatians were to his teaching about Jesus.

In any case, things had clearly changed. The Judaizers had begun to succeed in convincing the Galatians that Paul and his message of grace were not trustworthy.