Looking again at the Roman customs regarding employment, it’s clear that part of what just happened here is that James and John, like Simon & Andrew in the prior verse, aren’t just groupies but employees – they have become sons of Jesus, and he has become the head of their house. Now they work for him. When they preach or perform miracles, it is as an extension of Jesus has said or done these things. We can imagine that they were all on message and well practiced. “Pack your bags or kiss your ass – Rome is coming!”
Jesus has the authority to call people immediately into his service, away from fathers and brothers. They will go where he goes; they will do as he bids them.