1. You will all fall away (27-28)
Jesus knew his disciples' weakness. He knew that though they loved him, they were under the power of death; so they were full of fear. In the moment of crisis they would all run away. But Jesus did not despair. He saw even their running away from the point of view of God's history--as a fulfillment of Scripture. Most importantly, he planted in them hope in his resurrection, gave them a clear direction to repent, and assured them that he would welcome them when they came back.
2. Peter's self-confidence (29-31)
Peter loved Jesus. He was unconditionally committed to him. He said that he would be faithful to Jesus even if they all ran away. But his bold words rested on confidence in himself, not on confidence in God. He did not know himself nearly as well as Jesus knew him. By predicting Peter's denial, Jesus opened a way for Peter to be restored after his failure.
Application: Lord, teach me to depend on you and not on myself, and give me the humility to repent and come back to you when I fail.
One Word: Jesus restores those who fail and repent