Peter and Barnabas at Antioch; Acts 15:36 – 39,

Church History: Date: A.D. 49-50
36 Some time later Paul said to Barnabas, "Let us go back and visit the brothers in all the towns where we preached the word of the Lord and see how they are doing." 37Barnabas wanted to take John, also called Mark, with them, 38but Paul did not think it wise to take him, because he had deserted them in Pamphylia and had not continued with them in the work. 39They had such a sharp disagreement that they parted company.

This was a private quarrel between two ministers, no less than Paul and Barnabas, yet it ended well. Barnabas wanted his nephew John Mark to go with them. We should suspect ourselves of being partial, and guard against this in putting our relations forward. Paul did not think he was ready or worthy of the honor, he said he was not fit for the service. He had previously departed from them without their knowledge, or without their consent (Acts 13:13).