Mark 1:14-15 tell us that after John the baptist was arrested, Jesus began to preach the gospel in Galilee saying "The time is fulfilled, and the kingdom of God is at hand, repent and believe in the gospel." This is how Mark chooses to sum up Jesus' proclamation and ministry. As the first words out of Jesus' mouth in Mark's narrative, they are paradigmatic for all that Jesus is about. Jesus has come to proclaim that God's reign has come to earth. The day for which Israel has been waiting has finally arrived. God would finally reign with his righteousness and peace over all the earth.
There could hardly be a more important announcement that could be made. God's reign coming to earth would be the most transformative, cataclysmic, and world-changing event in history. We would expect some pretty awesome displays of power from someone who is making such a major claim about himself. In fact, the few verses leading up to this point in Mark's story already lead us to expect pretty tremendous things. We've already seen the sky ripped open, seen the Spirit of God descend, and heard a voice from heaven. So now that Jesus has made the biggest claim of all, that God's reign itself is at hand, we might expect some unimaginable demonstration of Jesus' strength and authority to come next in Mark's story.
Instead, Jesus goes and calls some fisherman to follow him so that he can make them fishers of men. Where are the miraculous displays of power? Where are the world changing events? If Jesus is going to begin campaigning for the reign of God on earth by surrounding himself with a select group of disciples, he could at least find some people with more power and influence than mere fisherman! How are they going to help him change the world? How will they help Jesus bring God's reign to earth?
That is one of the things I find continually fascinating about God's kingdom as opposed to the fading kingdoms of this world. We build our kingdoms on power, wealth, fear, military might, and political influence but eventually someone else is able to accumulate more of those than we can and our kingdom fails. God builds his kingdom out of fishermen who follow the crucified and risen Lord and it is the one kingdom that will never fail.