We would like to think that since we are followers of Jesus, everything is going to be just fine, and we are all always going to get along with one another. But life simply does not work that way.
Paul and Barnabas (who had been Paul’s mentor) apparently had such a rough disagreement over the inclusion of John Mark on what would become Paul’s second missionary journey that they seemingly said to one another, “Hope the screen door doesn’t hit you on your way out!” There is no indication that they ever spoke or worked together again. We know from his letters that Paul was ultimately reconciled to John Mark. As for Barnabas, we never hear from or about him again. We don’t know if Paul and Barnabas ever reconciled. While it may have happened, Luke does not tell that story. What we do know is that God used Paul, and Barnabas, and John Mark, and Silas, and many, many others for His holy purposes.
And God can use you, even if and when you have a falling out with someone in your family or a friend or even someone in your Bible study. Let God work. Something great may come of it!