I love John's Gospel. Why? Because over and over people don't understand. They don't get it. Even the disciples in John 20 - they don't understand at first.
We live in an egotistical day and age where we think we, by the powers of our reason, know and understand everything. We don't. We can only know by God opening the Scriptures and revealing Himself to us thereby. John gets that. John teaches that. John constantly warns me against trusting my reason or knowledge and instead to be focused on the Word.
John preaches against our day and age - it's such a wonderful thing.