What gospel did Paul share with the Jerusalem believers in Galatians 2?
Paul communicated to the Jerusalem believers the same gospel he preached among the Gentiles, doing so privately to those of reputation. He refused to yield to demands that Gentiles keep the Law and be circumcised, so that the truth of the gospel might continue with Gentile believers such as the Galatians.
Paul writes in Galatians 2 that 14 years after his conversion—dated A.D. 37, making this A.D. 51—he went up by revelation to Jerusalem. There he communicated to the Jewish believers “that gospel which I preach among the Gentiles.” He did this privately to those of reputation, lest he had run in vain. In the following verses, the same dispute as Acts 15 appears: Jewish believers insisted Gentiles must keep the Law and be circumcised. Paul refused subjection for even an hour and did not back down, so the truth of the gospel might continue with Gentiles such as the Galatians.