As we know from Acts 11 Barnabas and Saul had been sent from Antioch to Jerusalem with provisions for the prophesied famine that was to hit the Roman Empire. Here at the beginning of chapter 13 they have returned and we are given the names of the Elders of the church at Antioch. Barnabas, Saul and the other elders are all praying and fasting and God tells them to 'Set apart for me Barnabas and Saul for the work to which I have called them.' And so they did.
Barnabas and Saul travel to Cyprus. Here Saul becomes known as Paul; his Hebrew name is changed to that of a Roman one. While in Cyprus Paul rebukes a false prophet who then instantly becomes blind. Because of this the proconsul (the leader of the Roman army in Cyprus) believed in Jesus. They then go onto Pisidian Antioch.
However, something more than a man becoming blind and an army leader coming to faith has happened while they were away. Saul has become Paul and has now been passed the baton from Barnabas to be the lead elder. It is from here that we now no longer read Barnabas and Saul but Paul and Barnabas. Why?God had a mission for Paul, one He had told him about when Ananias prayed with him to restore his sight. He said to Paul 'a light for the Gentiles, that you may bring salvation to the ends of the earth' Barnabas knew this mission and from as soon as he had tracked Saul down he had encouraged him. We are called into a body. We are called to encourage one another in the things that we do. if God has given someone a word or a vision we are to support them and encourage them. Here we see how this encouragement and support is supposed to be for those coming up behind us.