In keeping with the goal of the middle section of Mark’s Gospel, your sermon must now explain to people what Jesus expects from those who wish to follow him. In essence, you are explaining to people what the Christian life involves and what true faith in Jesus should look like. Your explanation will need to highlight the fact that Jesus calls us to this life on account of who he is (Mark 8:29), what he has done for us (Mark 8:31), and what he will do when he returns (Mark 8:38).
31 And he began to teach them that the Son of Man must suffer many things and be rejected by the elders and the chief priests and the scribes and be killed, and after three days rise again.