The Gospel of John is traditionally attributed to one of Jesus’s original 12 disciples, John, the son of Zebedee (not to be confused with John the Baptist). According to early Christian sources, John was the longest-living and last-surviving of the disciples, and he is said to have written (in addition to the gospel) the book of Revelation and three New Testament letters: 1 John, 2 John, and 3 John. The gospel itself, however, makes few internal claims toward an identifiable author—the title is a latter addition to the manuscript tradition, and the only self-referential attributions are to a character identified as “the disciple whom Jesus loved” (see 13:23, 19:26, 20:2, 21:7, 21:20), or, more traditionally, the “beloved disciple.” Some scholars have called into question the identification of John as the author, suggesting instead that the gospel might hail from a later period of early Christian development, perhaps from another author in the Johannine circle. The evidence in either direction is not strong enough to make a firm conclusion, so one can find scholars across the spectrum defending multiple positions on the authorship question.

Tied to the question of the gospel’s authorship is that of the date of its composition.