What does John 21:20 mean?
After His resurrection, Jesus has met the disciples in Galilee (Matthew 28:9–10). He has performed yet another miracle to prove Himself (John 21:4–8). As He restored Peter to his calling as a disciple (John 21:15–19), Jesus predicted the way in which Peter would die. Using poetic language, He indicated Peter's fate was to by martyred by crucifixion. Tradition says Peter even asked to be nailed upside down, feeling unworthy to die the exact same way as did Christ.Standing nearby is John (John 13:25), who once again refers to himself in indirect terms (John 13:23; 19:26; 21:24). Here, he confirms that he was the one referred to in the account of the Last Supper when Judas left. Peter, John, and James were the inner circle of Jesus' disciples (Matthew 17:1; Mark 14:33; Luke 8:51). It would be natural for Peter to wonder what would happen to John. That's exactly the question he will ask in the next verse (John 21:21). Jesus won't criticize Peter for asking. He simply reminds Peter there is no need for him to know; Peter can focus on his own faith.