Several years ago, the editor in chief of Christianity Today recounted several conversations that he had had with pastors in his denomination. The pastors told him that when they preached from the Sermon on the Mount – you know, things like “Blessed are the meek,” “Blessed are the peacemakers,” “Love your enemies and pray for those who persecute you,” or especially, “Turn the other cheek.” When they preached from the Sermon on the Mount, people would come up to them afterwards and say, “Where did you get those liberal talking points?” But when the pastors would say, “I was literally just quoting the words of Jesus,” the people would not say, “Oh, sorry, I didn’t realize that.” Instead, they would say something to the effect of, “Okay, but that won’t work anymore. That’s weak.”
This is essentially what Peter did with Jesus in today’s Gospel. Peter, and most other people of his time hated the Roman oppressors in their land, and they were expecting a messiah that would come in with a mighty fist and power unseen before, and wipe out the enemies of Israel.