What did Paul admonish the Galatians to do when they were pressured to keep the Law?
Paul admonished the Galatian Gentile churches not to give in to the Judaizers, who insisted Gentiles must embrace Judaism and keep the Law to be saved. He reminded them they were not under the Law but under grace, so they should not surrender to that pressure.
Les explains that Paul had to hurriedly write this little letter to the Galatian churches in Asia Minor because the Judaizers were following him everywhere and would not give up. They maintained that Gentiles could not be saved unless they embraced Judaism and kept the Law. Paul's purpose was to tell the Galatians they were not under the Law but under grace, and to admonish them not to give in. Chapter 4 then uses Abraham's two sons, Hagar/Ishmael and Sarah/Isaac, as an allegory, but the core admonition is to resist the legalizers and not surrender to their pressure.