‘Jesus replied, “If I want him to remain alive until I return, what is that to you? As for you, follow me.”’ (John 21:22 NLT).

After Jesus told Peter the manner in which he would someday die for his witness, he asked about John’s future. Peter asked, “What about him, Lord?” The Lord responded that he shouldn’t worry about the plan God had for John’s future. He should focus on following Jesus, not on what happens to John.
John, who was probably the youngest disciple, perhaps still a teen when he started following Jesus, was in fact the last living disciple. He died around the year 100 AD. He was boiled in oil by the Romans but survived. He was exiled to the Island of Patmos where he wrote the book of Revelation. He eventually returned to Ephesus where most accounts state that he died peaceably. All of the apostles died a martyr’s death, except for John. The disciple who Jesus loved lived to see the gospel successfully carried into the next century.