The point of the Gospel of John is to demonstrate that Jesus is God so that the reader of the gospel would trust his soul into the care of this Jesus. Folks who cannot see the divinity of Jesus in the gospel of John have not yet understood the gospel. In fact, the reality of the deity of Jesus Christ fills the New Testament. If you don’t know Jesus as the incarnate God, then you don’t yet know him at all. He will not be accepted as a teacher or a moral leader or a good man–or even a prophet! He must be accepted as God the Son if he would be your Lord and Savior.
Here is a nice, summary article on the teaching of Jesus as God in the New Testament.