Identifying John in His Gospel. In John’s Gospel he never refers to himself by his name John. He is spoken of either as one of the sons of Zebedee or as the disciple whom Jesus used to love. When he speaks of John the Baptizer, unlike the other Gospel writers he calls the Baptizer only “John.” This would be more natural for one of the same name to do, since no one would misunderstand about whom he was speaking. Others would have to use a surname or title or other descriptive terms to distinguish whom they meant, as John himself does when speaking of one of the Marys.​—Joh 11:1, 2; 19:25; 20:1.

Viewing John’s writing in this light, it becomes evident that he himself was the unnamed companion of Andrew to whom John the Baptizer introduced Jesus Christ. (Joh 1:35-40) After Jesus’ resurrection John passed Peter by as they ran to the tomb to investigate the report that Jesus had risen. (Joh 20:2-8) He was privileged to see the resurrected Jesus that same evening (Joh 20:19; Lu 24:36) and again the following week. (Joh 20:26) He was one of the seven who went back to fishing and to whom Jesus appeared. (Joh 21:1-14) John was also present at the mountain in Galilee after Jesus rose from the dead, and he personally heard the command: “Make disciples of people of all the nations.”​—Mt 28:16-20.

Writership. Though the book does not name its writer, it has been almost universally acknowledged that it was written by the hand of the apostle John. From the beginning, his writership was not challenged, except by a small group in the second century who objected on the ground that they considered the book’s teachings unorthodox, but not because of any evidence concerning writership. Only since the advent of modern “critical” scholarship has John’s writership been challenged anew.

The internal evidence that the apostle John, the son of Zebedee, was indeed the writer consists of such an abundance of proofs from various viewpoints that it overwhelms any arguments to the contrary. Only a very limited number of points are mentioned here, but the alert reader, with these in mind, will find a great many more. A few are:

(1) The writer of the book was evidently a Jew, as is indicated by his familiarity with Jewish opinions.​—Joh 1:21; 6:14; 7:40; 12:34.

(2) He was a native dweller in the land of Palestine, as is indicated by his thorough acquaintance with the country. The details mentioned concerning places named indicate personal knowledge of them. He referred to “Bethany across the Jordan” (Joh 1:28) and ‘Bethany near Jerusalem.’ (11:18) He wrote that there was a garden at the place where Christ was impaled and a new memorial tomb in it (19:41), that Jesus “spoke in the treasury as he was teaching in the temple” (8:20), and that “it was wintertime, and Jesus was walking in the temple in the colonnade of Solomon” (10:22, 23).

(3) The writer’s own testimony and the factual evidence show that he was an eyewitness. He names individuals who said or did certain things (Joh 1:40; 6:5, 7; 12:21; 14:5, 8, 22; 18:10); he is detailed about the times of events (4:6, 52; 6:16; 13:30; 18:28; 19:14; 20:1; 21:4); he factually designates numbers in his descriptions, doing so unostentatiously.​—1:35; 2:6; 4:18; 5:5; 6:9, 19; 19:23; 21:8, 11.

(4) The writer was an apostle. No one but an apostle could have been eyewitness to so many events associated with Jesus’ ministry; also his intimate knowledge of Jesus’ mind, feelings, and reasons for certain actions reveals that he was one of the party of 12 who accompanied Jesus throughout his ministry. For example, he tells us that Jesus asked Philip a question to test him, “for he himself knew what he was about to do.” (Joh 6:5, 6) Jesus knew “in himself that his disciples were murmuring.” (6:61) He knew “all the things coming upon him.” (18:4) He “groaned in the spirit and became troubled.” (11:33; compare 13:21; 2:24; 4:1, 2; 6:15; 7:1.) The writer was also familiar with the apostles’ thoughts and impressions, some of which were wrong and were corrected later.​—2:21, 22; 11:13; 12:16; 13:28; 20:9; 21:4.

(5) Additionally, the writer is spoken of as “the disciple whom Jesus used to love.” (Joh 21:20, 24) He was evidently one of the three most intimate apostles that Jesus kept nearest to him on several occasions, such as the transfiguration (Mr 9:2) and the time of his anguish in the garden of Gethsemane. (Mt 26:36, 37) Of these three apostles, James is eliminated as the writer because of his being put to death about 44 C.E. by Herod Agrippa I. There is no evidence whatsoever for such an early date for the writing of this Gospel. Peter is ruled out by having his name mentioned alongside “the disciple whom Jesus used to love.”​—Joh 21:20, 21.