And there arose a sharp disagreement, so they [Barnabas and Paul] separated from each other.
One of our ministers used to have a saying, "The best of men are mere men at best." That is true of Christian men too! It's hard to think of two better men, better Christian men, than Barnabas and Paul, yet here we read that they had 'a sharp disagreement' - no doubt tempers flared. Why were they fighting? It was about a young man named John Mark. Mark had gone with Paul and Barnabas, who was probably his uncle, to help them on part of their first missionary journey, but he turned back and went home. Did he think it was all too dangerous? Or was he homesick? So Paul didn't want to take Mark with them the next time, and Barnabas did. So the disagreement ended up with Barnabas taking Mark to Cyprus, and Paul took a man called Silas on another visit to the churches that had been planted on his first visit. Happily all came right in the end as Paul came to value Mark's work and he spoke well of Barnabas too and the Gospel continued to spread.
Christians still fall out at times and it is never a good thing — indeed it can make us look really bad in the eyes of the world when they might say, "These are the people who are supposed to love one another." It is a bad witness and should make us ashamed unless the disagreement is really over a vital matter of Christian truth. Jesus does want us to stand up for the truth but always in a gracious way.
Dear Lord, help me to be a person of peace, but always true to your word. Amen.