Paul is Unique
Paul the apostle has a unique position in the New Testament. He was the man who transitioned the largely Jewish church that we find in the book of Acts to the largely Gentile church that we find at the end of the book of Acts. Not only was he a powerful evangelist and missionary, he was the critical transitional agent in the book of Acts and the New Testament. Paul had a unique job.
For this reason I, Paul, the prisoner of Christ Jesus for the sake of you Gentiles--
2 if indeed you have heard of the stewardship of God's grace which was given to me for you—(Eph 3:1-2).
Paul was designated as the apostle to the Gentiles, the non-Jews. He had a unique stewardship. His stewardship was to teach the revelation that Jesus gave him personally that both the Jews and the Gentiles should be equally united in the body of Christ. Both the Jews and the Gentiles would have equal standing before God, and both will no longer be under the law but instead they will have a living relationship with God the Father through Christ.