Mark 1:14-18: in context

This passage is the beginning of Jesus's public work in Mark, and the timing marker matters: after John was arrested. The man who prepared the way has been taken by Herod, and that is when Jesus goes into Galilee to preach.

His message is compressed into one sentence. The time is fulfilled, the kingdom of God has come near, repent and believe the good news. Two announcements and two imperatives, and the announcements come first. Something has happened, so respond to it.

Then the calling. He walks by the Sea of Galilee and sees Simon and Andrew casting a net, because they were fishermen. Follow me, and I will make you fishers of men. And immediately they left their nets and followed him. Mark gives no lead-up, no prior conversation, no deliberation. The men are working, and the work becomes the metaphor for what they are being asked to do instead. Their skill is not discarded, it is redirected. In the next verses James and John leave their father in the boat with the hired men, which is the detail that makes the cost visible. What am I already good at that could be pointed somewhere else without being wasted?