The author of the Gospel of John is John the beloved disciple, the Apostle and the one who was imprisoned on the Island of Patmos. This is the same John who also wrote the letter known as 1 John.
The letter of 1John has numerous concepts which are typically Johanine which are not used in the same way by other authors, thus stamping it with his character.
Comment: Actually there is one group who are willing to accept the evidence and another group who doesn't. Those who accept the abundant evidence which exists regarding Johanine authorship, have no problem with the reasonable proposition that John was the author. Those who don't accept the evidence would assert that we don't know who else wrote these works, since no other author has evidence to support them and no extra-biblical source close to the event postulated an alternative.
Evidence in Favor of John the Apostle Being the Author Internal Evidence: The proposition that the author of the Gospel of John is 'the disciple whom Jesus loved' and also the one who leaned on His breast at supper (21:20 cf. 21:7) and that the same person is indeed the apostle John is supported by a number of lines of evidence under three main points:
1. He was evidently a contemporary of the events described:
The writer was personally known to the High Priest and entered his residence along with Jesus on the night when Jesus was arrested (18:15). This author alone mentions the fact that it was the servant of the High Priest who had his ear cut off by Peter (18:10). This author deals with questions which are relevant to the period prior to AD 70 and not with controversies which were occurring in the second century connected with the Gnostic and Ebionite groups. (cf 6:15; 11:47-50) Many other details indicate contempoaneity with the events described.
2. He was Jew of Palestine:
The opening words of the book demonstrate an acquaintance with Hebrew (cf Genesis 1:1). On three occasions there are quotes from the Hebrew (12:40; 13:18; 19:37). There is intimate knowledge displayed regarding the Hebrew festivals viz. the Festival of Booths (7:2 Tabernacles KJV) the Feast of Dedication (10:22) and the Passover (21:13,23; 6:4; 13:1;18:28). Jewish customs and ways of thinking are familiar to the author eg. questions about purification (3:25;11:55), marriage customs, especially the method of arranging the waterpots (2:1-10); customs relating to burial (11:38,44; 19:31,40). Knowledge of the geography of Palestine is demonstrated such as the descent from Cana to the Sea of Galilee (2:12) and also the fact that Jacob's well is deep (4:11). Specific places such as Ephraim (11:54), Mount Gerizim (4:20), Jerusalem and the Kidron valley (18:1), Bethsaida and Siloam (5:2; 9:7), and Golgotha (19:17 etc).
3. He was John, the beloved disciple.
This can be deduced in a general sense from the above facts. He indicates the precise hours when particular events took place (1:39; 4:6,52; 19:14). He records quotations of the disciple Philip (6:7; 14:8), Thomas (11:16;14:5), Judas (14:22), and Andrew (6:8-9). He leaned on the breast of Jesus at supper on the night of the betrayal (13:23-25) and was among the three 'inner circle' of Peter, James, and John. Peter is distinguished from this author by name in 1:41-42;13:6,8 and James had become a martyr very early, long before the Gospel was written (Acts 12:2). He has a particular way of introducing himself (John 13:23; 19;26; 20:2; 21:7,20). These facts cumulatively make it difficult to come to any other conclusion, but that John was the author of the Gospel which bears his name.
Source: The New Unger's Bible Dictionary, Merril F. Unger, Moody, Chicago. 1988. p 701.
Authorship of 1 John
Like the Gospel of John, this letter also does not state the name of its author. However there is strong evidence both internal and external that it was written by John who was the son of Zebedee and the brother of James (Mark 1:19-20). There are indeed some strong similarities between the Gospel of John and this letter such as distinctive Johanine phrases, a limited vocabulary (as expected from a fisherman, unlike a learned scholar) and the frequent contrast of opposites.
External evidence includes the testimony of the many of the early church fathers among which are Papias, Polycarp (himself personally acquainted with John), and Irenaeus that both works are from the pen of a single author, the apostle John.
While John is generally considered to be "the disciple whom Jesus loved," there is a growing number of Christians who, upon very detailed examination of key scriptures, believe it may have actually been Lazarus. The actual authorship of the Gospel of John has been in dispute for some time. Readers are referred to "The Discliple Whom Jesus Loved" book.
Principles of New Testament Authorship and Attribution It must be remembered that the Christians of the New Testament era were particularly interested in who wrote what. They had this concern in that they were concerned that what they were being taught had Apostolic and thus full truthful authority. This, in contrast to examples of spurious and mythological teachings as evidenced in for example, the Gospel of Thomas.
Thus, the early Christians were interested in authority which included either eyewitness testimony or direct access to it in the cases of Mark and Luke. In relation to John, if there were some persons who believed Lazarus, or anyone else for that matter, to have been the author. The fact that there is unanymity around the authorship of John is telling, particularly in the light of the diversity that would have been expected had anyone else been the author or if the author was unknown.
