Scriptural Reference:
The prediction of Peter's martyrdom is found in the Gospel of John, specifically in John 21:18-19. This passage occurs after Jesus' resurrection, during one of His appearances to the disciples by the Sea of Galilee.

Context and Setting:
Following His resurrection, Jesus appeared to His disciples multiple times, providing them with final teachings and instructions. In John 21, Jesus engages in a poignant conversation with Peter, reaffirming his role and mission. This dialogue takes place after the miraculous catch of fish and the shared breakfast on the shore, symbolizing fellowship and restoration.

The Prediction:
In John 21:18-19 , Jesus says to Peter:
"Truly, truly, I tell you, when you were young, you dressed yourself and walked where you wanted; but when you are old, you will stretch out your hands, and someone else will dress you and lead you where you do not want to go."
Jesus said this to indicate the kind of death by which Peter would glorify God. After this, He said to him, "Follow Me."

Interpretation and Significance:
The phrase "stretch out your hands" is traditionally understood as a reference to crucifixion, a form of execution that Peter would eventually face. Early Christian tradition holds that Peter was martyred in Rome under Emperor Nero, crucified upside down at his own request, feeling unworthy to die in the same manner as his Lord.

This prediction serves multiple purposes within the narrative and theological framework of the New Testament. Firstly, it underscores the cost of discipleship, highlighting the ultimate sacrifice that following Christ may entail. Secondly, it reaffirms Peter's restored position among the apostles after his earlier denial of Jesus (John 18:15-27). Despite his past failures, Peter is entrusted with a significant role in the early Church, and his martyrdom is seen as a final act of faithfulness and devotion.

Theological Implications:
Peter's predicted martyrdom is a profound testament to the transformative power of Christ's resurrection and the work of the Holy Spirit. It illustrates the theme of redemption and the possibility of restoration after failure. Peter, once fearful and denying, becomes a bold proclaimer of the Gospel, willing to lay down his life for the sake of Christ.

Moreover, this passage emphasizes the sovereignty of God in the lives of His followers. Jesus' foreknowledge of Peter's death assures believers that their lives and destinies are in God's hands, providing comfort and courage in the face of persecution and trials.

Legacy and Influence:
Peter's martyrdom has been a source of inspiration for countless Christians throughout history, encouraging them to remain steadfast in their faith amidst adversity. His life and death exemplify the call to take up one's cross and follow Jesus, regardless of the cost. The Church honors Peter not only as a foundational apostle but also as a model of repentance, leadership, and ultimate sacrifice for the glory of God.