The Epilogue - Jesus Appears to His Disciples - the Restoration of Peter (John 21).
The Gospel appears to come to a perfectly satisfactory conclusion in John 20:30-31, which comes immediately after the confession by Thomas of ‘My Lord and my God' in John 20:28, which can be seen as the real climax to the Gospel. Indeed John 20:30 even seems to be a parallel statement to John 21:25. Thus chapter 21 gives the appearance of being a postscript to the Gospel. On the other hand there is no obvious break in the narrative and there is no easily discernible difference in style, vocabulary, or grammar. Thus different views are taken on the relationship of chapter 21 to the remainder of the Gospel. These may be stated briefly as:
(1) That it was written by the same author as Chapter s 1-20 at the same time as Chapter s 1-20 were written (with the possible exception of John 21:24, see discussion below on that verse).
(2) That it was written by the same author as Chapter s 1-20 but at a later time, even perhaps much later, towards the end of the author's life, (again with the possible exception of John 21:24).
(3) That it was written by someone other than the author of Chapter s 1-20 and added to Chapter s 1-20 at some later time.
But the fact is that if chapter 21 was indeed a later addition to the Fourth Gospel by a different author, it must have been added very early on, because no extant Greek manuscript lacks the last chapter, and there is no serious evidence in the manuscript tradition for it being a later addition. This is a very powerful argument against any suggestion of an ‘addition' which did not take place very shortly after it first began to circulate, for it means that no manuscript has survived without it..
As far as stylistic and linguistic evidence is concerned, nothing absolutely conclusive can be said. Some find similarities which point to identity of authorship, others find indications of divergence of style, and it is in fact clear overall that style and language in themselves are not sufficient grounds for coming to a final decision.
Thus most scholars make the decision for or against identity of authorship, not on the basis of stylistic or linguistic evidence, but on the basis of its content and logical argument flow. But, given the similarities easily observable, while this might be used to argue as to whether the chapter was written immediately as part of the whole or added later as a postscript, the decision as to whether it denotes a different author must be very subjective given the short length and nature of chapter 21.
What can certainly be said is that the writer, if he was not John himself, was very familiar with John's Gospel and wrote in full sympathy with his style and method. He does for example not mention either John or James except under the title ‘those of Zebedee' (but see Matthew 26:37), he speaks of ‘the disciple whom Jesus loved', he calls Peter ‘Simon Peter' and calls him the ‘son of Joanes', he calls Thomas ‘Didymus'. If it is not John it is someone trying unnecessarily hard to sound like him.
In our view therefore the reasonable position is to see it as a deliberate postscript by John to the main Gospel so that the main Gospel can end with Thomas' statement, while at the same time being a postscript added before the actual distribution of the Gospel. Its aim is threefold. Firstly to illustrate the total dependence of the disciples on Jesus for fruitfulness, secondly to indicate the full restoration of Peter and to confirm his first call and thirdly to remove the ideas lying behind certain false rumours about John and the second coming. It is, of course, also a testimony to the resurrection and supports the fact of resurrection appearances in Galilee.