It is widely known that John's gospel omits the name of one disciple -- that of John the son of Zebedee, preferring instead to identify him by phrases such as "the disciple whom Jesus loved". At the end of the gospel, in John 21:24, the author of the gospel identifies himself as being the unidentified disciple. He writes,
This is the disciple who is bearing witness about these things, and who has written these things, and we know that his testimony is true.Is there any independent evidence to corroborate the author's claim to be this disciple? If so, then the argument for Johanine authorship rests on being able to demonstrate the identity of this disciple -- and I think a very convincing case can be made for him being John the son of Zebedee by a process of elimination.
That being the case, consider what we find in John 18:15-16:
Simon Peter followed Jesus, and so did another disciple. Since that disciple was known to the high priest, he entered with Jesus into the courtyard of the high priest, but Peter stood outside at the door. So the other disciple, who was known to the high priest, went out and spoke to the servant girl who kept watch at the door, and brought Peter in.It makes sense to identify this other disciple as John -- first because he is unidentified (which is how John is treated consistently in John's gospel) and second because "the disciple whom he loved" (which I take to be the apostle John) was certainly present at the cross, since we read in John 19:26-27:
When Jesus saw his mother and the disciple whom he loved standing nearby, he said to his mother, “Woman, behold, your son!” Then he said to the disciple, “Behold, your mother!” And from that hour the disciple took her to his own home.It is thus a reasonable inference to take the other disciple from John 18:15-16 to be John the son of Zebedee. What then is the significance of him being "known to the high priest"?
In John 18:10, we read,
Then Simon Peter, having a sword, drew it and struck the high priest's servant and cut off his right ear. (The servant's name was Malchus.)How did the author of John's gospel come to know the name of the high priest's servant? Indeed, he is the only gospel author to give us this detail. This makes sense, however, if indeed John was someone who was known to the high priest. This corroborates the Johanine authorship of John's gospel. It is not by itself conclusive, but when taken in conjunction with other independent lines of evidence (both internal as well as external), one has a persuasive cumulative case to take John's gospel as penned by the disciple John.