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.
Jude the Apostle
Some Biblical scholars reject this theory, however, holding that Jude and Thaddeus did not represent the same person. Scholars have proposed alternative theories to explain the discrepancy: an unrecorded replacement of one for the other during the ministry of Jesus because of apostasy or death; the possibility that "twelve" was a symbolic number and an estimation; or simply that the names were not recorded perfectly by the early church.