37Barnabas wanted to take John, also called Mark, with them,
38but 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.
39They had such a sharp disagreement that they parted company. Barnabas took Mark and sailed for Cyprus,
40but Paul chose Silas and left, commended by the brothers to the grace of the Lord.
41He went through Syria and Cilicia, strengthening the churches."
between Paul & Barnabas
P & B had a serious dispute over Mark (because he gave up in Pamphylia.) Because of the disagreement the 2 great preachers formed 2 teams, opening up 2 missionary endeavors instead of one.
God works even through conflict and disagreements. Later, Mark became vital to Paul's ministry (Colossians 4:10) Will Christians always agree? We must learn to solve our disagreements agreeably, in love and remember WWJD.
Paul's 2nd missionary journey, this time with Silas as his partner, began approximately 3 years after his first one ended. They covered many of the same cities Paul visited on his first journey. They stopped in Greece and laid the groundwork for the church there.