In this introductory word, we first need to see that there are two views concerning Christ in the four Gospels.
There is the physical view of Christ according to the synoptic Gospels—Matthew, Mark, and Luke. They are called synoptic Gospels because they bear the same view.
The second view is the mystical view, not the spiritual view, according to the Gospel of John. John among the four Gospels stands by itself, because all the other three Gospels are concerning Christ as a man. In Matthew we see Him as the King, in Mark as the Slave, and in Luke as the Man. The view in these Gospels is physical concerning Christ as a man, but John is concerning Christ as God.
This one person is of three periods. In order to understand this crystallization-study of John, we have to know the three periods of Christ.
Christ, the very God in eternity past, became flesh and lived in the flesh for thirty-three and a half years from His incarnation to His death as seen in the four Gospels. This is the stage of incarnation (John 1:14).
First, there is the Christ in the flesh, in incarnation. But in His resurrection He was transfigured to be the life-giving Spirit (1 Cor. 15:45b). This is the stage of Christ as the Spirit (the pneumatic Christ) in Acts and twenty-one Epistles (from Romans to Jude), from the resurrection of Christ to the beginning of the degradation of the church in about A.D. 60, before the martyrdom of Paul, who wrote his Second Epistle to Timothy in about A.D. 67, with many points related to the degradation. This is the stage of inclusion. The pneumatic Christ is the all-inclusive Spirit.
First, Christ was in the flesh in incarnation; second, He became the Spirit in resurrection; and third, He is the seven Spirits (the sevenfold intensified Spirit) in Revelation, from the degradation of the church to eternity. This is the stage of intensification. These three stages, or periods, of Christ are the three "i's"—incarnation, inclusion, and intensification.
The Gospel of John is a record of Christ living as a physical person but having His being all the way mystical; hence, a mystical record. He is a man, yet He is a mystical man, a mysterious man.