Jesus, while rejecting the role of a political and revolutionary leader type of messiah, sees his role as someone who is to suffer. Immediately after telling Peter not to go around saying that Jesus was the messiah, Jesus according to Mark, tries to teach the apostles about himself.
MK 8:31-33 "Then Jesus began to teach his disciples: `The Son of Man must suffer much and be rejected by the elders, the chief priests, and the teachers of the Law....' He made this very clear to them. So Peter took him aside and began to rebuke him. But Jesus turned around, looked at his disciples, and rebuked Peter."
Comment: The passage again reveals Peter's misunderstanding. You can almost hear him saying "Wait a minute: `messiahs' don't suffer; they are kings. Think `palaces' and `easy street;' forget this suffering stuff."