Men, who may be right on a particular issue, become wrong when they approach their brethren with any attitude short of godliness. Paul and Barnabus disagreed. Barnabus wanted to take John Mark on their journey and Paul did not wish for him to go. The disagreement was so strong that Paul and Barnabus parted ways. Among other things, we teach from this passage how men ought to behave when they disagree on matters of opinion.
Men can disagree on matters of opinion and maintain godly conduct.
Well, I m not talking about him, BUT Paul always did try to run the show. I fully support Brother Barnabus and am glad someone finally stood up to Paul. But that is how petty some of our attacks are. If they cannot find a doctrinal issue, they will settle for opinion. This attitude and activity is far from a stand for the truth.