John really finished his account of the gospel at the end of chapter 20. So why this extra chapter? As a tender shepherd, Jesus reaches out to restore  a fallen disciple. Many today would have insisted that Peter spend some time to go through a program of discipline and restoration to qualify himself for ministry once again. Not Jesus. He lovingly restores him and recommissions him into the frontline of ministry. In fact, Peter dominates the first 12 chapters of the book of Acts.