This chapter comprises mainly of Peter's statement to the Church leaders in Jerusalem about his meeting with Cornelius, so it is a repetition of chapter ten to a large degree. This reinforces the importance of the conversion of Cornelius for the Christian Church: Luke would not have used valuable papyrus if he had not understood this event to be crucial. It would have been easy for the Early Church to be assimilated into Judaism and become another small branch wholly consisting of Jews. Suddenly their eyes were open to a worldwide vision!
Peter's statement is a response to criticism from a section of the Christian leadership. These would likely have come from the Pharisees, who would be converts to Christianity, but still sought to maintain the Jewish purity laws. When Cornelius was converted, the thing to have done from their point of view was to circumcise him, so making him a proselyte in the same way as the Ethiopian eunuch.
Peter's actions were especially controversial because he had eaten with Gentiles and Peter does not defend himself but explains what happened when the Holy Spirit came upon them. He mentions in verses twelve that he had taken six people with him and in Law seven witnesses were necessary to prove a case completely. Peter gave clear evidence that God was in Cornelius' conversion and so nobody could stand against a movement of God.
The proof of Christianity is that it works, that it does change people, that the Holy Spirit comes on men and women and transforms them. This cannot be denied!
Luke continues with news about the spread of the Church, reporting that the Good News of Jesus spread to Gentiles as well as Jews and was received wholeheartedly by many. Barnabas is sent out to gather information about the spread of Christianity. The man with the biggest heart of love and encouragement was the one chosen: what a wise decision!
In the Early Church, there were three sets of leaders: firstly, apostles-who led the whole Church wherever it was to be found; secondly, elders-who led individual fellowships; and thirdly, prophets-who were not settled in one church, but spoke the will of God. The incident mentioned here is significant as it demonstrates that people had registered the importance of Church unity: it was unthinkable that one part should be suffering and another do nothing about it.