One of the reasons the story of Jesus is so believable is because it tells of so many failures. Jesus didn't come to destroy his enemies and establish an army that couldn't be stopped. He rode into town on a donkey and recruited faulty, fallible people to take up the cause after his own shameful death. Peter was no exception. His betrayal was poignant because this is the same Peter who Jesus praised for believing that Jesus was the Son of God, and now that belief is falling apart. There's some hope in that part of the story for those of us who sometimes struggle in our own faith.