Second Chances
When Paul wrote to Timothy, whom he considered his spiritual son, he said; "only Luke is with me. Get Mark and bring him with you, for he is useful to me for ministry." (2 Timothy 4:11) How remarkable that he was requesting Mark, also called John Mark.
On an earlier missionary journey recounted in Acts 13, John Mark had left Paul and his party in Perga and returned to Jerusalem. Though we aren't told Mark's reasoning, this was a serious breach to Paul proving him untrustworthy for the gospel work.
He felt this so strongly that later he and Barnabas got into a pretty serious disagreement over it. Barnabas wanted Mark to travel with them on another trip and Paul insisted he not go. "Then the contention became so sharp that they parted from one another. And so Barnabas took Mark and sailed to Cyprus; but Paul chose Silas and departed." (Acts 15:39-40)
What happened to change Paul's opinion of Mark so that he was now considered "useful to me for ministry" once more? Probably several things. Maybe Mark was a little immature to begin with and maybe Paul was a little too dogmatic. Over time, Mark grew and was seasoned. Paul softened as he saw how Mark matured and so was willing to re-evaluate his first opinion.
Be careful about writing someone off for good. Things change. People grow. God gives second chances and so should we.