Development of the New Testament canon a novelty in Irenaeus's time. "Against Heresies" 3.11.7 acknowledges that many heterodox Christians use only one gospel while 3.11.9 acknowledges that some use more than four. The success of Tatian's Diatessaron in about the same time period is "...a powerful indication that the fourfold Gospel contemporaneously sponsored by Irenaeus was not broadly, let alone universally, recognized." Irenaeus apparently quotes from 21 of the New Testament books and names the author he thought wrote the text. He mentions the four gospels, Acts, the Pauline epistles with the exception of Hebrews and Philemon, as well as the first epistle of Peter, and
New Testament people named John among Jews of the time. He is usually identified with the Mark mentioned in various epistles, and with Mark the Evangelist. This John is occasionally proposed as author of some of the Johannine works as well. Tarazi even goes so far as to attribute to him the Gospels of both Mark and John and all the other Johannine books. Five canonical books of the New Testament are ascribed to John and thus called collectively the "Johannine literature": Only in Revelation does the text itself name its author as John; the other Johannine works are ascribed to John only through their