"Barnabas wanted to take John, also called Mark, with them, but 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. They had such a sharp disagreement that they parted company. Barnabas took Mark and sailed for Cyprus, but Paul chose Silas and left, commended by the believers to the grace of the Lord." - Acts 15:37-40

Different Gifts with Different Callings Can See Conflicting Needs with Opposing Resolutions

When Paul and Barnabas left Antioch (in Syria) form their first missionary trip across the Island of Cyprus and then into Lycaonia and Galatia, they took John Mark along as a “helper.” (Acts 13:5) “Helper” is the translation of the Greek word “huperetes” which is made up of two Greek words: the first is the preposition “hupo-“ meaning “under” and the second, “eretes” means “rower” and is translated as “assistant,” “attendant,” “helper,” “minister,” and, even “officer.”
John Mark may have been taken along with Paul and Barnabas to serve as a first hand, eye-witness of Jesus' passion, death and resurrection. The Last Supper may have been held in the home of John Mark and his mother, Mary, which was where the early church met regularly as is seen in Acts 12:12 when Peter goes to join the church that was meeting in Mary's house when he is released from prison by an angel. John Mark may have followed Jesus and the disciples out to the Garden of Gethsemane on the night that Jesus was arrested and may have been the young man who is referred to in this account recorded by John Mark in his Gospel:
“Then everyone deserted him and fled. A young man, wearing nothing but a linen garment, was following Jesus. When they seized him, he fled naked, leaving his garment behind.” – Mark 14:50-52

On their first missionary trip Paul, Barnabas and John Mark made their way towards the treacherous country of Asia , Luke says that John Mark:
                “…left them to return to Jerusalem.” – Acts 13:13

The Greek phrase translated “left them” can mean “to depart" or "to desert.” In Acts 15:38, Paul labels John Mark’s actions on the coast of Asia as “deserted them.” So, when Barnabas, who is John Mark’s cousin (Colossians 4:10), desired to take John Mark along for the second missionary trip, Paul says, “No!” and, Barnabas says, “Absolutely, Yes!”
Luke says this resulted in “such a sharp disagreement” between Paul and Barnabas “that they parted company.” The phrase “sharp disagreement” is translated from “paroxysmos” which is used twice in the septuigint (LXX) to express “the furious anger” of God. The difference in opinion concerning John Mark might have been caused by the different perspectives and different callings God had given to Paul and Barnabas. Paul was called and gifted to take the message into the land of the foreign Gentiles where he would face unbelievable opposition. This is not a ministry for someone who is undecided and hesitant. Plus, it is a ministry that requires that the person be called and empowered by God. Someone could be hurt if they were counting on John Mark, who suddenly decided to turn and go home again. Paul made the right choice according to his gift.
But, Barnabas, whose name itself means “son of encouragement” was gifted and called to encourage people. Barnabas could help believers make their next step or find their next connection in their ministry. Barnabas did this for Paul twice. Once, when the Jerusalem church rejected Paul after his conversion (Acts 9:27), and then, again, when Barnabas went in search of Paul in the land of Cilicia because he felt Paul could benefit the Antioch church in Syria (Acts 11:25). So, what is a man like Barnabas going to do when he sees a young man like John Mark struggling to find his place in the ministry? Barnabas is going to take John Mark on a second missionary trip for a second try in the ministry every time. Barnabas also made the right choice according to his gift.
It is worth noting that this occurred in the year 49 AD, and 18 years later in 67 AD, Paul is in prison and needs a good scribe to help copy letters and take dictation for him, so Paul tells Timothy:
“Get Mark and bring him with you because he is helpful to me in my ministry.” – Second Timothy 4:11

Indeed, Mark was useful in the ministry! He traveled for several years with Peter serving as his scribe (First Peter 5:13) and writing Peter’s account of his days with Jesus and editing them into the book of Mark. Mark was not an apostle like Paul, nor was he the "son of encouragement" like his cousin Barnabas, but Mark was useful to both Peter and Paul, and to all the church, as a scribe, an editor and a writer.

Do I understand that at times people with different spiritual gifts and different callings will conflict?
Do I conflict with people in the church because of the ministry focus God has called me to?
I will recognize that different gifts have different focuses, so I will avoid conflict by continuing to use my gift while allowing other believers room to focus on God's call in their life.