Apostles
Later in the Gospel narratives the twelve apostles are described as having been commissioned to preach the Gospel to "all the nations", regardless of whether Jew or Gentile. Paul emphasized the important role of the apostles in the church of God when he said that the household of God is "built upon the foundation of apostles and prophets, Christ Jesus himself being the cornerstone".
Although not one of the apostles commissioned during the life of Jesus, Paul, a Jew named Saul of Tarsus, claimed a special commission from the risen Jesus and is considered "the apostle of the Gentiles", for his missions to spread the gospel message after his conversion. In his writings, the epistles to Christian churches throughout the Levant, Paul did not restrict the term "apostle" to the Twelve, and often refers to his mentor Barnabas as an apostle. The restricted usage appears in the Revelation to John.
Paul the Apostle and Judaism
Within the last three decades, a number of theologians have put forward other "new perspectives" on Paul's doctrine of justification, and even more specifically on what he says about justification by faith. According to Simon Gathercole, "Justification by faith" means God accepts Gentiles in addition to Jews, since both believe in God. Paul writes in his letter to the Romans, "For we maintain that a man is justified by faith apart from observing the law. Is God the God of Jews only? Is he not the God of Gentiles too? Yes, of Gentiles too, since there is only one God, who will justify the circumcised by faith and the uncircumcised through that same faith". Faith is the central component of Paul's doctrine of justification — meaning that Gentiles don't need to become Israelites when they convert to Christianity, because God is not just the God of one nation, but Gentile and Jew alike.