Now we may be certain that Polycarp would be likely to know the truth of the matter, and Irenæus declares that "_John, the disciple of the Lord who leaned on the bosom of the Lord at supper_, wrote the Apocalypse."[57] So we have here reliable evidence that John wrote both the Apocalypse and the book whose author leaned on our Lord's bosom at supper. Not only this from Polycarp. There is extant "The Epistle of Polycarp to the Philippians," which Irenæus believed to be genuine, and in it we find these words: "For whosoever doth not confess Jesus Christ hath come in the flesh, is antichrist." I compare this with the words in John's Epistle: "And every spirit that confesses not that Jesus Christ is come in the flesh, is not of God, and this is that spirit of antichrist." Our author says it is not a verbatim quotation. I say it is a quotation, if not verbatim. It is acknowledged that the author of the First Epistle of John and the Fourth Gospel is the same, the ideas and style being so much alike. "The two writings," says Rénan, "present the most complete identity of style, the same peculiarities, the same favourite expressions."
It is impossible to doubt that Polycarp would have learned from John himself whether he was the author of a Gospel; and if Irenæus had never heard Polycarp allude to the Gospel as John's, he could not have believed in it as he did, and have plainly stated that John wrote it and the Apocalypse. There would have been in this case a justifiable inference from "silence." If Polycarp in his teaching had never alluded to John's Gospel, it would have been so strange that Irenæus would have deemed it spurious altogether, and unworthy of the estimation with which he regarded it; for it is one of the four Gospels that he fancifully likens to the four corners of the earth, the four principal winds, and the four wings of the Seraphim. It is to be remembered that our author acknowledges Irenæus so regarded all the four Gospels, for he alludes (p. 91) to "the arbitrary assumption of exclusive originality and priority for the four Gospels" by Irenæus, Tertullian, and Epiphanius. It is evident that this Fourth Gospel could not have first appeared as late as A.D. 150, but must have been in existence long before; and on the testimony of Irenæus, through Polycarp, from John himself, its authenticity may be considered established.