The world diversity of religion has caused division, strife, and contention, which differ from the reality of unity; evidently, this is the same issue that we have today.
About Paul and Barnabas parting their ways is because they had different instruction by the Holy Spirit. Barnabas, which was full of the Holy Spirit (Acts 11:24), he persuaded the Jerusalem disciples to receive Paul (9:27). He was sent to receive the Gentiles at Antioch (11:19-24). He guided Paul from Tarsus to Antioch (11:25, 26). He came with Paul on his first missionary journey and accompanied Paul on his first missionary journey. It was the Holy Spirit that told Barnabas and Saul (Paul) to separate for a good cause, “Separate me Barnabas and Saul for the work whereunto I have called them,” and from thence they started on what is called Paul’s first missionary journey “Acts 13:2-4