Going all the way back to Abraham's first encounter with Yahweh in Genesis 12, "call narratives" comprise some of the most important passages in Scripture. They're either described or presumed by every sacred author. Such an event is essential to their message.
It's no accident, for instance, that almost immediately after Mark describes God's baptismal annunciation to Jesus, he has the Galilean carpenter begin his public ministry by calling others to help him carry out his commission.
Jesus first invites Simon and his brother Andrew to ". . . come after me, and I will make you fishers of human beings." Daniel Harrington points out in the New Jerome Biblical Commentary, "This (fishers of human beings) metaphor is best interpreted against the background of their occupation . . . ." In other words, Jesus wasn't saying that he was sending them out to "catch" people. He simply was trying to impress upon them that people would replace fish at the center of their lives.
This is a key element in all biblical calls: the person called must readjust his or her priorities. What once was important is now peripheral; what formerly was on the perimeter is now at the center.
Having been preconditioned in my early life and later seminary training to hear today's gospel narrative as Jesus calling his first four "priests," I missed much of what Mark was trying to convey in the passage. Jesus is calling them to be his first Christians, not his first priests. Every element in the narrative applies to every person who agrees to be a follower of Jesus. This is how all Christians are expected to react to the call they receive.
That's why much in made of the fact that, along with the first set of brothers, James and John ". . . left their father Zebedee in the boat along with the hired men and followed him." None of the four sets a date in the future to change their occupation, or asks for time to dispose of their assets. Their response to Jesus' call is immediate and total.
Yet perhaps the most fascinating element of biblical calls is that the called are never informed exactly where or to what they're being called. Our sacred authors believe it's essential that calls be "generic." The only specific element is that "you're to follow me." God always invites us to follow a person, not a system or a program, but a living person.
That personal element is at the root of Jonah's problem. He doesn't particularly like Yahweh's personality. That's why he originally "ran away from Yahweh." The prophet demands some predictability in God; specifically that Yahweh should carry out the word he gives the prophet to proclaim.
In the case of Jonah's mission to the Ninevites, Yahweh's message is clear: "Forty days more and Nineveh will be destroyed!" We can only imagine how disturbing it is for the prophet to discover that ". . . God repented of the evil had threatened to do to them, he did not carry it out." Unpredictable things happen when one gives oneself to a person instead of a theological system. Perhaps every call from God should be accompanied with the warning, "Hang on!" Lord knows (literally) where it's going to take us!
No wonder Paul warns his Corinthian community about the rough, jolting faith-ride they're beginning. It's like nothing they've experienced before. ". . . Let those having wives act as not having them, those weeping as not weeping . . ." Once one says "Yes!" to God, things will never be the same; the unexpected will be the expected.
Maybe it would be good to paraphrase John Donne's well-known poetic line, "Never send to know for whom the bell tolls . . ." Today we should hear, "Never send to know whom God calls. God calls you."