John presents Jesus as God, the Fountain of Life, The Word, The Christ. And at the same time he focus on Jesus as a human being who weeps, gets tired, and full of compassion. Jesus does not seem to hide who he was like the other gospels.
Scholars say that it was written between the years 90 and 100 of our era. They also say that the main purpose of this gospels was to terminate heresies.
The Gospel of John is also the fourth of the gospels in the bible and it's not part of the synoptic gospels. It mentions a dinner in honor to Jesus where the details even contradict a similar dinner in the other gospels. It must be a different dinner. He is the only one that mentions the story of Nicodemus.