Paul now turns from teaching the gospel to addressing specific things that the Galatians are doing wrong. In particular, verses 8-10 call out the Judaizing influence that seeks to re-enslave them. Before being Christians, they were slaves to the evil forces of the world, and now turning to the Law is tantamount to returning to those evil forces. Observing “days and months and seasons and years” suggest both Pagan and Jewish religious practices, wherein people are required to do stuff for their god(s). But as verse 9 celebrates, we enjoy a relationship with God, not mere servitude.
Then Paul adds what may be the most personal touch in the entire epistle (v12-15). He appeals to them reminding them of when they looked after him when he was sick, desiring for that positive relationship to continue. So now, he asks, what has changed? Why are they turning to false teachers? He points out that the Judaizers are using exclusion as a lure to attract them in and make them zealous for their own teachings. He appeals to them, “little children” – the only time Paul ever calls anyone this in writing – revealing the height of his passion and concern for them, and he expresses his wish to be with them in person so they can talk this over.