If you want to learn more about how world class biblical scholars view the gospel of John then this lecture by Dr James D. G. Dunn is highly informative. Like most New Testament scholars Dunn is a believing Christian. However, as a distinguished scholar he acknowledges that Jesus could not have said the famous self-identifying assertions in the gospel of John – the I am sayings:
I am the way, the truth, and the life.
Truly, truly, I say to you, before Abraham was, I am.
I am the light of the world.
I am the bread of life.
I am the resurrection and the life.
These utterances were created (ie invented) by the author of John’s gospel. They do not go back to Jesus. How so? See Dunn’s argument from 13 minutes onwards. His conclusion is shared by at least 99% of mainstream critical scholars.