When one examines the different approach and calling of the apostles that existed before the cross, one can differentiate between the two.  The Bible specifies the job description of the first Apostle in Matthew 10: 1-8: “He called his twelve disciples and gave them authority over unclean spirits, to cast them out and to heal every disease and sickness. The names of the twelve apostles are these: first, Simon called Peter, and Andrew his brother; James the son of Zebedee, and John his brother; Philip and Bartholomew, Thomas and Matthew the publican; James the son of Alpheus, Thaddeus, Simon the Zealot, and Judas Iscariot, who also betrayed him. These twelve Jesus sent out and commanded them, saying, do not go the way of the Gentiles, and into any city of the Samaritans do not enter:  But go rather to the lost sheep of the house of Israel. As you go, preach, saying: “The kingdom of heaven is at hand. Heal the sick, cleanse the lepers, and raise the dead, cast out devils; Give these things without charging, since you received them without a cost.”

This passage of the Bible is quite clear, the same Jesus gives instructions to his twelve disciples, that they were not to go to the Gentiles (non-Jews,) on the other hand, for the apostle Paul the instructions to ministry are different after the cross:

The writer of Acts 9:15 states, speaking of Saul of Tarsus: ” The Lord told Ananias, “Go! I’ve chosen this man to bring my name to nations, to kings, and to the people of Israel.” Also in Acts 13: 46-48 says it this way: “Paul and Barnabas told them boldly, “We had to speak the word of God to you first. Since you reject the word and consider yourselves unworthy of everlasting life, we are now going to turn to people of other nations. The Lord gave us the following order: ‘I have made you a light for the nations so that you would save people all over the world.’” The people who were not Jews were pleased with what they heard and praised the Lord’s word. Everyone who had been prepared for everlasting life believed. In addition, Paul himself writes in Romans 11:13 the following: Now, I speak to you who are not Jewish. As long as I am an apostle sent to people who are not Jewish, I bring honor to my ministry.

After carefully examining these passages one can say with certainty that Paul is the Apostle send to the Diaspora. Being himself a Jew by birth God send him to show His grace and mercies to all the people groups of the world, panta ta ethne.