Teachers Commentary notes this about Galatians 3
In Galatians we have Paul’s first powerful defense of the Gospel. Some from the Pharisee party in Judea who had trusted Christ apparently retained their zeal for the Mosaic Law. They traveled to the churches Paul had founded, and taught that the Gentile Christians must be circumcised and must keep the Law of Moses to be saved. In essence, they said that to be a true Christian a Gentile must become Jewish in lifestyle, and live by the Old Testament’s code.
Paul confronted this view, insisting that what these men taught was a different gospel from the Gospel of God’s grace in Jesus Christ. Paul insisted that there can be no mixture of Law and grace in the Gospel of Christ without robbing the Gospel of its power.
Now, in the extended and carefully argued bulk of Galatians,
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