John the Apostle
New Testament author

Church tradition has held that John is the author of the Gospel of John and four other books of the New Testament – the three Epistles of John and the Book of Revelation. In the Gospel, authorship is internally credited to the " disciple whom Jesus loved " (ὁ μαθητὴς ὃν ἠγάπα ὁ Ἰησοῦς, o mathētēs on ēgapa o Iēsous) in John 20:2. John 21:24 claims that the Gospel of John is based on the written testimony of the "Beloved Disciple". The authorship of some Johannine literature has been debated since about the year 200.

In his 4th century Ecclesiastical History, Eusebius says that the First Epistle of John and the Gospel of John are widely agreed upon as his. However, Eusebius mentions that the consensus is that the second and third epistles of John are not his but were written by some other John. Eusebius also goes to some length to establish with the reader that there is no general consensus regarding the revelation of John. The revelation of John could only be what is now called the Book of Revelation. The Gospel according to John differs considerably from the Synoptic Gospels, which were likely written decades earlier. The bishops of Asia Minor supposedly requested him to write his gospel to deal with the heresy of the Ebionites, who asserted that Christ did not exist before Mary. John probably knew of the Gospels of Matthew, Mark, and Luke, but these gospels spoke of Jesus primarily in the year following the imprisonment and death of John the Baptist. Around 600, however, Sophronius of Jerusalem noted that "two epistles bearing his name... are considered by some to be the work of a certain John the Elder" and, while stating that Revelation was written by John of Patmos, it was "later translated by Justin Martyr and Irenaeus," presumably in an attempt to reconcile tradition with the obvious differences in Greek style.

Until the 19th century, the authorship of the Gospel of John had been attributed to the Apostle John. However, most modern critical scholars have their doubts. Some scholars place the Gospel of John somewhere between AD 65 and 85; John Robinson proposes an initial edition by 50–55 and then a final edition by 65 due to narrative similarities with Paul. Other scholars are of the opinion that the Gospel of John was composed in two or three stages. Most contemporary scholars consider that the Gospel was not written until the latter third of the first century AD, and with the earliest possible date of AD 75–80: "...a date of AD 75–80 as the earliest possible date of composition for this Gospel." Other scholars think that an even later date, perhaps even the last decade of the first century AD right up to the start of the 2nd century (i.e. 90 – 100), is applicable.

Nonetheless, today many theological scholars continue to accept the traditional authorship. Colin G. Kruse states that since John the Evangelist has been named consistently in the writings of early Church Fathers, "it is hard to pass by this conclusion, despite widespread reluctance to accept it by many, but by no means all, modern scholars."

Modern, mainstream Bible scholars generally assert that the Gospel of John has been written by an anonymous author.

Regarding whether the author of the Gospel of John was an eyewitness, according to Paul N. Anderson, the gospel "contains more direct claims to eyewitness origins than any of the other Gospel traditions." F. F. Bruce argues that 19:35 contains an "emphatic and explicit claim to eyewitness authority." The gospel nowhere claims to have been written by direct witnesses to the reported events.

Mainstream Bible scholars assert that all four gospels from the New Testament are fundamentally anonymous and most of mainstream scholars agree that these gospels have not been written by eyewitnesses. As The New Oxford Annotated Bible (2018) has put it, "Scholars generally agree that the Gospels were written forty to sixty years after the death of Jesus."
change_case:capital_word_frequency[2]