‘And Barnabas was minded to take with them John also, who was called Mark, but Paul thought not good to take with them him who withdrew from them from Pamphylia, and went not with them to the work.'
Barnabas was clearly happy to fall in with the idea, but when the matter was further considered Barnabas firmly insisted that John Mark came with them. Paul on the other hand did not feel that he could agree with this. In his view Mark could not be depended on. He had failed once on their previous mission, he could fail again. He was unreliable. And experience had shown him how important it was that all the party on any of their journeys were reliable.
The fact that Barnabas was so insistent helps to support the idea that part of the reason for Mark's ‘failure' had been due to his loyalty to Barnabas. Thus Barnabas would feel that he must respond with a similar loyalty. Furthermore it was of the nature of Barnabas to seek to encourage those who were having difficulties. He had done it with Paul. He was an encourager. He would not desert Mark.
Paul, however, was single-minded, and at this stage in his life unyielding. To his mind Mark had failed God and could therefore only be a hindrance in the work. He might well have seen in him what appeared to him to be a lack of dedication which he feared could act as a barrier that could hinder the work of the Spirit and their spiritual usefulness. He may well have considered that compromise was unacceptable.
We need not therefore see Paul and Barnabas as falling out with each other in any personal way. It was rather a question with each of principle, on which, as strongminded men, they were taking up a different viewpoint, the result being that they simply agreed to differ and go their separate ways. We may see it as a mature Christian decision on both sides, and it unquestionably turned out for the good of the work, for by separating and forming two parties they would be able to accomplish twice as much. In fact Barnabas, who in his gracious way had probably given way to Paul on much, was no doubt now able to expand and develop his ministry in his own way, in a way that he could never have done while he was with Paul.