MacArthur on Mk 6.5 “Jesus didn’t do many miracles there”

This statement does not mean that His power was somehow diminished by their unbelief. It may suggest that, because of their unbelief, people were not coming to Him for healing or miracles the way they did in Capernaum and Jerusalem. Or, more importantly, it may signify that Christ limited His ministry both as (1) an act of mercy, so that the exposure to greater light would not result in a worse hardening that would subject them to greater condemnation, and (2) a judgment on their unbelief. He had the power to do more miracles, but not the will, because they rejected Him. Miracles belonged among those who were ready to believe.

John F. MacArthur Jr., The MacArthur Bible Commentary (Nashville: Thomas Nelson, 2005), Mk 6:5.