Peter goes from high to low in just a few short verses. For denying the way of the Cross, and trying to dissuade Jesus from following the same, Peter takes on the role of the Tempter, even if unwittingly. Jesus’ harsh reaction shows that a great deal is at stake not only Jesus’ saving atonement, but also the life his disciples expect to live.
The Cross is not only for Jesus but for anyone who would follow him. Suffering for the sake of the kingdom is a requirement for coming after Jesus, and the broad way that avoids suffering leads not to resurrection but to destruction.
Today, the health and wealth message that says that God is waiting on the right amount of faith to "bless" you with riches or success, and its more cultivated cousin, in which following Jesus is really the path to unlocking one’s inner potential are the very Satanic counterfeits the Lord demands be put behind us. Nothing is more fatal to Christian discipleship than misconceiving it as the path to a better earthly life. Suffering is not the obstacle in the Christian’s path, it is the Way itself.