John 21:19 New International Version (NIV)
19 Jesus said this to indicate the kind of death by which Peter would glorify God.Then he said to him, “Follow me!”
Jesus patterned his questions to Peter to mirror the denials. This gave Peter three chances to show his love to Jesus. Jesus then repeats his the invitation for Peter to follow him. This was the same invitation that Peter got when he first met Jesus. In the beginning, how little we know about ourselves, but as we walk with Jesus and follow him, we get to know him more and more.