John Mark learned about the power of communal prayer when he saw Peter miraculously freed from prison through the prayers of those gathered at his mother's house (Acts 12:12ff).
John Mark learned about serving the poor and building unity between Jewish Christians and Gentile Christians when he accompanied Barnabas and Paul on a relief mission (Acts 12:25).
John Mark learned about spiritual warfare and his own weaknesses when he quit the first missionary journey of the early Church (Acts 13:13).
John Mark learned that we don't always get a second chance when Paul refused to take him on a second missionary journey (Acts 15:38).
John Mark learned that we sometimes do get a second chance when Barnabas took him on a missionary journey (Acts 15:39).
John Mark learned more about Jesus and His Church when he was spiritually adopted by Peter (1 Pt 5:13).
John Mark learned about Jesus, the Church, prayer, the poor, unity, mission, people, and life. Then the Lord chose John Mark to write one of the Gospels. The Holy Spirit graced John Mark to write some of the most important words ever written.
The Lord is teaching you now. If you learn your lessons, you will see the Holy Spirit work through you in wondrous ways.