What does John 21:18 mean?
Peter denied Jesus three times (John 13:35–38; Luke 22:61–62). Three times, Jesus made Peter affirm his love and faith (John 21:15–17). Jesus called Peter after a miraculous provision of fish (Luke 5:5–11). Having performed a similar miracle yet again (John 21:4–8), Jesus is about to restore Peter's calling (John 21:19).First, Jesus makes a prediction which is both dire and comforting. The description of being dressed and led, with outstretched hands, is a poetic foreshadowing of crucifixion. The following verse confirms this. Church tradition indicates Peter was crucified and asked to be hung upside down out of respect for Christ's similar death. While this seems like a terrible fate, it implies something Peter would find encouraging: his faith would never fail him again. That doesn't mean Peter would be perfect (Galatians 2:11–14). It does mean his passionate desire to serve Jesus would define the rest of his life.