We have testimony from Jesus that disciples can have Him speaking and acting through them so we can believe He Himself was in John as John revealed truths about Jesus so Jesus was revealing truths about Himself through John. Two great truths are revealed by Jesus about Himself through John. Firstly that He is the incarnation of the Logos and here through John Jesus uses a clear reference back to sayings of Heraclitus about the Logos that is effectively the objective truth about all things that might or might not be known or acknowledged by humans but even so is nevertheless true. This is of course found in the prologue of John's gospel. Secondly, Jesus showed John Himself at the start of His revelation recorded in the Book of Revelation as identical with the one like a son of man seen by Daniel and through John, Jesus had it recorded how He looked such that the description is a match with the description Daniel gave of this mysterious being. So Jesus identified Himself through John as a mysterious being who interacted caringly with Daniel hundreds of years before Jesus was born. So we can put these two together and in these verses Jesus is showing Himself to be a mysterious and seldom seen being like a human but angelic who was with God in times long before His birth on earth and was the actual truth about all things manifested as a human-like being. This Jesus still is even though He was born a real actual human and died and rose again to live forever. It is Jesus who reveals all this about Himself through John His beloved disciple.
