While I'm on the subject of the Incarnation (the doctrine that God became human), I would like to post a few points once gleaned from Stephen T. Davis' wonderful book _Logic and the Nature of God_.
Davis initiates his discussion by citing John Hick, who avers that the claim "Jesus is fully God and fully man" (VERE DEUS, VERE HOMO) is in effect saying that a circle is fully square and fully circular. Hick argues that the claim is "devoid of meaning" and logically impossible. If an object is fully square, then it cannot be fully circular (it cannot be P and ~ P at the same time and in the same sense). Therefore, the proposition "Jesus is truly God and truly man" is deemed to be incoherent.
This point can also be illustrated by juxtaposing the properties of God and the properties of man. God is omniscient, but man is not omniscient; God is omnipotent, but man is not omnipotent; God is A SE ESSE, but man derives his existence from God.
God is immortal; man, however, is not. It seems that divine properties rule out finite properties subsisting in the same entity simultaneously? The predicates essential to God appear to be incommensurable with the predicates proper (essential) to man. Davis realizes this point and concludes that in order to coherently formulate the Incarnation doctrine--one must deny the essential nature of God's omniscience and furthermore, one must also state the Incarnation teaching in a way that does not imply Jesus has all of the essential properties of God or all of the essential properties of man SIMPLICITER. But surely this view is not in harmony with Chalcedonian orthodoxy. It reflects the kenoticist views of the 19th century.
In conclusion, I think that Davis' treatment of this issue shows the ineluctable conundrums that result when one tries to make the Jesus of the New Testament fit one's preconceived theological and philosophical notions of our Lord. He is an ardent defender of the Incarnation, but he has realized the logical difficulties associated with believing that God became man.