Why was Paul frantically responding in the book of Galatians?

Paul was responding urgently because false teachers had infiltrated the Galatian congregations he established in Asia Minor, insisting that salvation required circumcision and observance of the Law of Moses, not faith alone. He opposed this works-based error that was bombarding the churches.

Les explains that Paul frantically responded to false teaching that had come into the congregations he had established in Asia Minor, which is today the land of Turkey, especially the southern half where Galatia was located. These false teachers were claiming the Galatians could not be saved by faith and faith alone; they had to be circumcised and keep the Law of Moses. Les notes that while we do not have circumcision as such today, many other things fall into the same category of works, and such works-righteousness does nothing but bring down the anathema of God Himself.

Why was Paul so urgent and frantic when he wrote the book of Galatians?

Paul was urgent because false teachers had infiltrated the Galatian congregations he had established in Asia Minor, teaching that salvation required circumcision and keeping the Law of Moses, not faith alone. He responded frantically to defend salvation by faith and faith alone against this works-based distortion.