1 After these things Jesus showed Himself again to the disciples by the sea of Tiberias, in addition He showed Himself in this way.
2 Simon Peter and Thomas (the one called Didymus, twin) and Nathanael, the one from Cana of Galilee, the sons of Zebedee, and two other disciples of Him were together.
3 Simon Peter said to them: “I’m going to fish”. They said to him: “We are also coming with you”. So they went into the boat, but that night they caught nothing.
The ending of chapter 20 appears to infer that John had brought his gospel record to an end. This may well be true. Therefore, there are those who firmly suggest that chapter 21 is not the work of John; some suggest that it is the work of some of the elders in Ephesus.
It is thought that John spent his last years in Ephesus. The suggestion is that the elders of the church in Ephesus would have known John well; consequently they would have known the events that we have in chapter 21, and probably wrote them.
However, this ignores the words of verse 24:
24 This disciple is the one who bears testimony and has written about these things, and we know that his testimony is true.
It is obvious that John wrote these words, and not somebody else.
John may well have thought that he had brought his gospel record to a conclusion with the end of chapter 20, but then the Holy Spirit prompted him to add the events recorded in chapter 21. There is no good reason to think otherwise.
We see the same kind of thing in some of the letters of the New Testament.
2 Peter 5.10-11 is an example of this.
The exaltation of Peter appears to bring his letter to a conclusion, but he then adds a few more verses, in a similar way as John did with chapter 21.
The Sea of Tiberius is the Sea of Galilee.
Tiberius was a town situated on the Western side of the Sea of Galilee. It was a town that Herod Antipas enlarged and improved. He renamed it Tiberias in honour of Emperor Tiberias Caesar.
The disciples would have made their way to Galilee because He had made a promise to the women that He would meet them there:
“Don’t be afraid! Go tell My brothers to leave for Galilee, and they will see Me there” – Matthew 28.10 (NLT).
They obediently followed His command and went to Galilee, and it is John who tells us how Jesus came to them.
There are blessings for us all as we meet His Divine appointments with us.