Donald Bloesch commenting on Karl Barth’s christology, as well as his own assimilation of Barth’s framework.
With Karl Barth I hold to the preexistent humanity of Jesus Christ, but not in the sense that the man Jesus preexisted in heaven as a separate being (Barth would agree). I contend that God the Son took upon himself the identity of the man Jesus and thereby united himself with humanity. By “humanity” I am thinking not of flesh and bones but instead of individuality, embodiment, vulnerability and dependency. The Son of God could become human because the Godhead already embraces characteristics that we attribute to humanity. Barth insightfully declared that “genuine deity includes in itself genuine humanity.” Those who are closer to Greek metaphysics might object that this position makes God an anthropomorphic being. Divinity, however, does not signify timeless essence (as in the Greek view) but dynamic existence (as in the Hebraic view). Because God is a Trinity he interacts dynamically within himself, and this is why he can also go out of himself and interact dynamically with his human subjects.
To affirm the preexistent humanity of Jesus means that the incarnation was not an absolute beginning. It implies that there is continuity between the historical Jesus and the eternal Christ. The full meaning of the incarnation is not simply that the Word became flesh, but that Jesus Christ assumed human flesh (1 Jn 4:2).
. . . I do not begin in my theological speculation with an abstract idea of a preexistent man nor with the dogma of the preexistent Word or Son of God (a christology from above). Nor do I begin with a historical investigation of the available evidence concerning the life and death of Jesus (a christology from below). I begin with the incarnation itself—-God assuming human flesh in a particular time and place in history (a christology from the center). By seeing the eternal God in the Jesus of history we are then able to understand why this God is already named Jesus Christ and how Jesus’ humanity becomes a mode of his divinity. To claim that Jesus is victor (Johann Christoph Blumhardt) is also to claim that Jesus is God—-not God in the abstract but God in humanity, God in history. This is the God who enters the world of sin and death in order to overcome sin and death by making atonement for sin on the cross and by breaking the power of death through rising from the dead and ascending into heaven. (Donald Bloesch, “Jesus Christ: Savior & Lord,” 142-43)