I thought I would lighten the mood here. I hope everyone will take this for what it's worth, this is not a polemic against Christianity but more of a scholarly point that is considered in a secular light even by most theists.
The three synoptics, Matthew, Mark and Luke, share certain interesting similarities. John is left out in the cold. It is a conundrum for reasons related to sourcing the synoptics that the earliest physical evidence we have for any of the four is a fragment that most probably comes from gJohn. That is really not an issue in priority by itself, and not why I am posting this.
John was the last of the gospels to be admitted into the canon unofficially, and even officially with some dissent. The arguments then are born out by evidence today; that John was much closer to a Gnostic work than the synoptics, and too close for the comfort of some.
If we look at the last three chapters, it reads somewhat as if the ending was chapter 20, and 21 was an addition, with 22 being an even later addition (or the two were possibly alternate endings included in a way to string them together as one).
Chapter 21 has the story of Jesus seeing the fishermen on the lake, and when they could catch nothing, he tells them to cast their nets on the other side of the boat. They caught plenty of fish, and then Peter jumps in and swims to shore to be with Jesus, followed by the boat, and then the net. This is important for later.
So these fishermen were amazed, and they realized who he was. The mood is celebratory and pious at the same time at this point. Here is God-on-Earth, and right there in front of them. Of course you expect them to be excited. But something strange is noted; the number of fish they caught is mentioned, exactly 153. That has been a question for theologians for centuries; in all the excitement, who the heck stopped to count the fish?
It turns out that 153 is a peculiar number. 1^ 3 + 5^3 + 3^3 equals 153. It is also a triangular number. 3 is triangilar; 1+2=3. 6 is triangular; 1+2+3=6. 10 is also, 1+2+3+4. If you do this all the way to 17, ie: 1+2+3...+15+16+17, you come up with 153. It is also very important to early trigonometry and math, because without decimals the simplest way to represent the square root of 3 is 265/153. This was definitely no news to Euclid, and was probably common knowl;edge to Pythagorus.
One way the Hellenes passed down mathematical knowledge was through stories involving a learned mentor. Plato, a student of Pythagoras, recounts a story about some fishermen and Pythagoras guessing the number of fish in their net. A lot has been made of the similarities of John chapter 21 and this story, but trust me when I say it was not a word for word copy, in spite of what some skeptics insist. In fact we don't really know the whole story, just that it was similar and that it represented a way to memorize the square root of 3, or 265/153. At this point it could be coincidence, or it could have been a common literary device that "just fit the situation" for the author of John. Just keep this in mind.
On another tangent, everyone is familiar with the fish symbol used to denote Christianity. This symbology is older than Christianity by at least 300 years, and it was in vogue in the first century which also marked the entry into the age of aquarius. The Astrological symbol for aquarius itself is a variation of this, although fortune tellers and new-agers don't always realize this. No matter.
The symbol itself comes from something called the Vesica Piscis
, or the "measure of the fishes". This was illustrated by Euclid and was an important tool in geometric proofs concerning the square root of 2, 3 and 5, the relationships of equilateral triangles, right triangles and demonstrating Thale's law (any two triangles with two of the same angles and the length of one side are similar). It turns out that the ratio of the length to the width of the Vesica Piscis, or this fish shape, is always on the order of 265/153. Its just a convenient way to demonstrate the constant.
Now back to Plato and his work Timaeus
(you may recognize the name from gMark as Bartimaeus, or Bar-Timaeus, "son of Timaeus"). He tells a story which itself describes the cosmology of accepted by the later neo-platonists, which still later became a cosmology for most Gnostic thought. Reconstructions of the diagram are pretty esoteric, but they make sense in both a geometric and a philosohical sort of way.
Remember the idea that gJohn was at least partly gnostic-seeming to some of the ante-Nicenes? And today it is still considered at least partly Gnostic? That comes in large part form the idea that chapter 21 was a later, pseudo-gnostic addition.
Instead of trying to lay this all out with formatting, I'll link you to a Christian website which explores this in general detail. If you are interested just do some google research. It shouldn't shake anyone's faith, but if you are curious about the secondary meanings one can derive from the bible it should provide hours of insight.
Scroll down to "The Logos" section.
Vescica Piscis description from Wiki: