Who was chosen to take the Gospel of Grace to the whole world?
Paul was God's chosen vessel to take the Gospel of Grace beyond Israel to the whole world. The context contrasts him with Peter, James, and John, noting that their authority had slipped and that Paul was not behind the chiefest apostles.
Les explains that Paul repeatedly made the point that Peter, James, and John were not above him. Now they have slipped off the scene, lost all their authority, and this man is God's chosen vessel to take the Gospel of Grace, not just to the nation of Israel, but to the whole world. Les also notes that Paul suffered throughout the whole twenty years of his ministry with one beating after another, one imprisonment after another, and constant opposition from his own countrymen, the Jews, while the twelve did not have to endure that.