Mark’s Gospel is seventeen chapters long, and it breaks evenly into two halves at its spine in the middle at Chapter Eight. That’s where we are today. The first seven and a half chapters over and over show Jesus to be the Savior. They do this by describing numerous divine miracles, by quoting devils declaring him to be the Savior, by demonstrating the many ways in which he fulfilled prophesies made about the Savior.
Coming to the halfway point in his Gospel, with all the evidence laid out before the disciples and us readers, Peter brings the first half of the Gospel to an end by declaring with finality that Jesus is the Christ, the Savior.
In the very next verse, with its now being established that Jesus is the Savior, Mark opens the second half of his Gospel, with Jesus telling us all how he would save us. He will do it by surviving all the suffering the powers of evil can throw against him.
Each of the four Gospels was written for its own specific purpose. John wrote to show the world that Jesus is the Messiah, and we have life through him. Matthew wrote to tell us that Jesus, far from departing from Jewish tradition, is actually the one who sums up all of Jewish tradition. Luke wrote to give us an orderly, convincing account .
People were saying that it was impossible that Jesus, as one suffering an execution, could be the Savior. Mark, after convincingly proving Jesus to have been the Savior; went on to show that far from being scandalous, the suffering of Jesus was actually his means of saving us.