John 21:18-22

“Truly, truly, I say to you, when you were younger, you used to gird yourself and walk wherever you wished; but when you grow old, you will stretch out your hands and someone else will gird you, and bring you where you do not wish to go.”  19 Now this He said, signifying by what kind of death he would glorify God. And when He had spoken this, He said to him, “Follow Me!”

20 Peter, turning around, saw the disciple whom Jesus loved following them; the one who also had leaned back on His bosom at the supper and said, “Lord, who is the one who betrays You?” 21 So Peter seeing him said to Jesus, “Lord, and what about this man?” 22 Jesus said to him, “If I want him to remain until I come, what is that to you? You follow Me!” 

This is the last mention of Peter from the gospels. Jesus was telling him that he would die a martyr’s death, but not until he was old. Peter being a young man would have plenty of time to serve God.

You remember that Peter declared to Jesus that he was ready to die for Him. Well, Jesus was telling him now that he would later in life get that opportunity.

Then an unlikely thing happened. Peter pointed to John that was nearby, and said, what about him? Will he also die for You? Peter, even at the last encounter with Jesus, was showing his immaturity. I think he was just a little jealous of John—of his close relationship with Jesus (and it seemed that the disciples were constantly debating who was the greatest). But Jesus quickly shut it down. He wanted Peter to focus on his own ministry, and what he himself would do for Him. He should have no business knowing what kind of ministry John would have and whether he would die for Him of not.