Where is scriptural reference that the John on the Isle of Patmos is the same John who was among the 12 disciples?
The Book of Revelation begins by stating, “The Revelation of Jesus Christ, which God gave unto him, to shew unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John.” (Revelation 1:1). Three times in this chapter, and five times in this book, John mentions his name. “(Revelation 1:1, 1:4, 1:9, 21:2, 22:8). Because John uses no descriptive words concerning himself, we can naturally assume that he was familiar to those to whom he was writing. Surprisingly, although John wrote the Gospel of John and the three epistles of John, he never mentions his own name in any of these books.
There is no scriptural reference that shows that the John that wrote the Book of Revelation is the Apostle John. However, second-century sources indicate that John was exiled to the Isle of Patmos. For example: Ignatius (35-107 AD…an early Christian writer and bishop of Antioch) writes of particular conclusive facts in that “Peter was crucified, Paul and James were slain with the sword, John was banished to Patmos, and Stephen was stoned to death by the Jews who killed the Lord.” The Apostle John’s exile matches what we find of the author as we read in Revelation 1:9, “I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ.” It is supposed that the Book of Revelation was written around AD 95.
Of course, there is no scriptural reference that John wrote any of his books. Neither are there scriptural references that Matthew, Mark, or Luke wrote their Gospels, either. Many of the authors of the different books of the Bible are identified by historians, not the Bible itself.
This should not be troubling to us as believers for we know who wrote every book, every chapter, every verse, and every word of the Bible. It was God, Himself as we read in 2 Timothy 3:16-17, “All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.” The term, “inspiration of God” literally means that all scripture was “God breathed”. The Bible is composed of HIS WORDS. We also read in 2 Peter 1:21, “For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.” Again, we see that the Word of God was written by the Lord as He used and inspired different men to write. The original canon of scripture is pure, perfect, and complete. (450.4)