1,2, and 3 epistles of John
In none of the NT epistles credited to John does the author identify himself. But, there is so great a similarity between the first epistle and the Gospel of John that most Bible scholars admit the common authorship of the two works. And a similar relationship ties the first epistle with the second and the second with the third.
Also, it is recognized that John wrote the book of Revelation. But how did the scholars reach this deduction? The New Testament mentions several men by this name, the Baptist, the son of Zebedee, who was one of the Twelve, John, who was surnamed Mark, and a certain relative of the high priest Annas (Acts 4:6).
Clearly, the author of the Revelation could not be John the Baptist, for that John was killed before the crucifixion of Jesus; nor is it possible that it was the relative of Annas, of whom there is no indication that he ever became a Christian. Also, there is little evidence that John Mark was the author of the Revelation. The style, wording, and approach of the second Gospel are simply different from those of the Revelation.
Almost universally early Christian tradition identifies John as the author of the Revelation. In fact, every Christian author until the middle of the 3d century believed that. These authors are Justin Martyr at Rome (c. A.D. 100–c. 165; Dialogue With Trypho 81), Irenaeus at Lyons (c. A.D. 130–c. 202; Against Heresies iv. 20. 11), Tertullian at Carthage (c. A.D. 160–c. 240; On Prescription Against Heretics 36), and Hippolytus at Rome (died c. A.D. 220; Who Is the Rich Man That Shall Be Saved? xlii).
In His service,