What were the Judaizers trying to do to the churches in Asia Minor?
The Judaizers were seeking to bring the Gentile believers in the churches of Asia Minor under the law and into legalism, pressuring them to adopt Judaic legal requirements instead of the grace gospel Paul preached. They deluged those churches with this pressure.
Les explains that Paul was writing to the churches in Asia Minor who were being deluged with Judaizers. Those Judaizers were trying to bring the Gentile believers under the law and legalism. Paul had established Gentile churches on his missionary journeys, then received word they were being tempted with legalism, so he hurriedly wrote this epistle. The gospel Paul preached among the Gentiles was something the Jerusalem Jews could not comprehend: God was going to the Gentile, pagan, idolatrous world to bring people to reconciliation with Himself outside of Judaism.