Summary: The claims of Jesus in the Gospel of John:
Conclusion: The Gospel of John, like the synoptic gospels, shows us that Jesus understood Himself to be divine, to have an exclusive relationship with the Father, to have been the promised Messiah, to have all authority in heaven and earth, to be related in parity-status with the Spirit and Father, and to be the central issue in the personal destinies of people.
But the words of Jesus in John also develop some themes a bit further. Jesus (in John) draws considerably more attention to His glorious and unique pre-creation state in heaven, with the Father. The complex relationships between the Father and Son (and Spirit) are focused on. And the mutuality of their work in the drama of redemption is recorded faithfully.
If it is fair to say that the Synoptics teach the deity of the Son, then it is probably equally accurate to say that the Gospel of John emphasizes the divine unity of the Father and Son.