The Gospel According to John

The Gospel of John was the last written and the most individual Gospel of the four. While the three synoptic gospels were written before the fall of Jerusalem and have specific audiences in mind, the Gospel of John was written long after the end of Jewish temple worship and not directed to a specific group or culture, but to the world as a whole. John's presentation is unique also, due to the fact that John focuses on Jesus the Savior, not the Kingdom of God. The synoptic gospels present Christ the Messiah who is offering the promised Kingdom of God to the Jews, in John the kingdom is only mentioned five times in three verses.

The primary purpose of this gospel is actually stated in the gospel itself, the reader doesn't have to dig for meaning or implied reasoning, it's all right there:

30 Therefore many other signs Jesus also performed in the presence of the disciples, which are not written in this book; 31 but these have been written so that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name. (John 20:30-31)

Another unique thing about John is that it only covers 20 days in Jesus' life on earth and not in sequence. John does not record Jesus' birth, genealogy, childhood, baptism, temtation, transfiguration and assention of Jesus, but instead begins with the fact that Jesus is God (John 1:1-4). John records no parables and this is the only gospel to refer to Jesus as the "Lamb of God", an image familiar to Jews. The Jews understood the sacrifice of a lamb symbolized the taking away of sin.

There are eight miracles recorded in John's gospel, and of them only the feeding of the five thousand appears in any other gospel leaving seven as unique to the Gospel of John. This is further evidence that John was written to the world and presented Jesus’ supernatural ministry identifying Him as God come in the flesh.

Study tells us that John apparently left Jerusalem just before or sometime during the Jewish wars (AD 65 - 69) and he spent rest of his life in Ephesus. During the reign of Domitian (AD 81 - 96) he was persecuted for being a Christian and was banished to the island of Patmos. There is where he received the Revelation of Jesus Christ and wrote it down, becoming the last book of the Bible. During the reign of Emperor Nerva (AD 97), John returned to Ephesus where he died during the reign of Trajan in approximately AD 98. He was the only one of the twelve disciples to die a natural death.

Historically there's no evidence that the Apostle John wrote the Gospel According to John, but then there's no historical evidence that anyone besides John wrote it. I've read a few articles that say that the author of John was a very close contemporary of Jesus, while others say that the author didn't know Jesus at all. Neither forms of these articles offer no real proof to hold up their claims, it's just a feeling that the authors of the articles have. 

Personally I believe that John was written by someone very close to Jesus, there's a familiarity with the Gospel of John that isn't present in the synoptic Gospels. To me it appears like the author is looking back in time with a soft wistful longing to go back and be with his beloved Jesus. Little things like the episode in John 20:1-4 show a slice of real life that doesn't appear in the synoptic Gospels. 

And why wouldn't John be close to Jesus - they were first cousins. Everyone knows that Jesus and John the Baptist was Jesus second cousin, but John, and his brother James, was Jesus' first cousins. Mathew 4:21 identify James and John as the sons of Zebedee, Mathew 27:56 tells us that the mother of Zebedee's children was at the cross when Jesus was executed, and Mark 15:40 identifies her as Salome. John 19:25 identifies Salome as Mary, Jesus' mother's, sister. Since families were very close back then, it goes without saying that Jesus grew up with James and John, which casts a new light on Matthew 20:20-21. You can almost hear Jesus saying "Aunt Salome, SERIOUSLY?!?"

So yeah, the author of the Gospel of John knew Jesus, intimately, lovingly, and deeply only as someone who grew up with Jesus and saw with his own eyes that Jesus was God could.