The Gospel of John is the second book written by one of Jesus' 12 disciples (quick, what's the other one?)
Scholars mostly agree that it was the last Gospel written down. It is not a synoptic Gospel (Matthew, Mark & Luke are.) That's a fancy way of saying that the Gospel of John's writing style and story line are "different". It's apparent from the first verse.
"In the beginning..." (1.1) Where have you heard that before? John is intentional, he takes his readers back to where it all began.
"In the beginning was the Word, and the Word was with God, and the Word was God." (1.1)
Unlike the story telling synoptics, the Gospel of John creates theology from the get-go. John immediately establishes that Jesus (the Word) is a) eternal b) co-creator and c) divine. He was "with" God in the beginning and through him "all things were made". Without him, "nothing" would have been made. (1:2-3)
(Do you remember how things were created in Genesis 1. Yup, it had to do with the "word"...God spoke.)
In addition, the Word (who is a him), is life and light...for all mankind. John recognizes that something bigger is at play...in fact a cosmic triumph of light over darkness.
Light is a big deal to John (it was also a theme in Luke). John is a mere witness to the light, not to be confused as the light (1:6-8).
We learn that the light can be for everyone. But some people just don't get it. Which is a huge bummer. Because when you get it, when you believe you get to become a child of God...a supernatural transaction.
Where Matthew and Luke see a baby, John sees God. His Immanuel - God with us, focuses not the the human aspect but the divine wrapped in flesh: "The Word became flesh and made his dwelling among us." (1:14)
This should cause us to pause. Cosmic deity wrapped in mortal, corruptible flesh. WILLINGLY.
During my time as a missionary in China, I had occasion to debate the merits of various religious beliefs. Hands down, the incarnation trumps all. Most religious systems are based on man's aspirations to live up to a "deity's" expectations. Jesus' plan was just the opposite: God came to us.
John reminds us that the Christmas birth story is one where the c0-creator of the universe folded omnipotence and omnipresence into flesh. The limitless became limited.
Because He loved us.
Truly this is "grace upon grace." (1:16)