John the Evangelist (d. ca. 110; יוחנן "The LORD is merciful", Standard Hebrew Yoḥanan, Tiberian Hebrew Yôḥānān), or the Beloved Disciple, is the name used to refer to the author of the Gospel of John and the First Epistle of John. Traditionally he has been identified with John the Apostle. Wikipedia
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St. Irenus also positively designates the Apostle and Evangelist John as the teacher of Papias, and neither he nor any other writer before Eusebius had any idea of a second John in Asia (Adv. www.newadvent.org/cathen/08492a.htm