The church at Galatia most likely consisted of two audiences: Jew and Gentile (non-Jew/non-Israelite) but predominantly Gentiles. Accordingly, Paul speaks directly and most prominently to those Gentiles who were being taught and encouraged by Jews to put adherence to the “works of the law” over faith in Christ as a means of obtaining and retaining justification and righteousness and (2) less so but still so to those Jews who were so teaching and/or so inclined to so adhere (Gal 3:1-9).
In either case, whether Jew or Gentile, Paul reminds them that they had received salvation and the accompanying Holy Spirit not by works of the law but by faith in Jesus Christ and him crucified and resurrected. Paul reminds them that according to God’s standard the law cannot justify them but justification comes through faith in Christ. He reminds them that righteousness cannot be obtained or sustained through the works of the law but only through faith in Christ (Gal 3:1-14, 26-29). This includes reminding them that the just shall live by faith. He reminds them that the law is not of faith; therefore he who seeks righteous by the law lives by the law and not by faith (Gal 3:11-12). He reminds them that they who are of faith is blessed with faithful Abraham (Gal 3:9). He reminds them that we are children of God by faith in Christ Jesus not by works of the law. (Gal 3:26-29). Yet he also warns them that we shall reap what we sow and therefore we are to not be weary in well doing (Gal 5:13; Gal 6:7-10; Gal 5:14-21; 5:22-26).
In Galatians Paul clearly is rebuking the Galatians for listening to those who say they must attend to the works of the law to include celebrations of certain times which it is reasonable to conclude he speaks of Mosaic sabbath days and feast days that some were saying they must observe to be righteous for certainly that which they observed before conversion were not counted as part of “works of the law”.
Now here Paul speaks as the apostles did in Acts 15 concerning circumcision; they say such works of the law are not necessary for salvation and are not a requirement for those in the family of God. Yet, neither say it is ungodly to be circumcised or participate in such days only that they are not a requirement under Christ.