I’m reading The Presence and the Power: The Significance of the Holy Spirit in the Life and Ministry of Jesus, by Gerald F. Hawthorne at the moment. It’s a relatively scholarly study of what you might call the interaction of the 2nd and 3rd members of the Trinity during the life of Jesus.
Hawthorne says that, “to many modern thinkers,” the incarnation of God as a human being “is inconceivable” (p. 40). He quotes John Knox as saying, “We can have the humanity without the pre-existence or the pre-existence without the humanity. There is absolutely no way of having both.” (Hawthorne cites “Knox, The Humanity and Divinity of Christ, 98, 106.”) Hawthorne (p. 41) also quotes C. F. D. Moule as saying, “We may have to admit inability to make a logical system out of the evidence, and be content to hold to, or be held by, both ends of the dilemma, confessing a mystery which cannot be rationalized withou doing injustice to some part of the evidence.” (Hawthorne cites “Moule, The Holy Spirit, 58.”)
I find these claims rather baffling. If (1) to be human is to be an image of God (as Genesis 1 seems to imply), (2) to be an image is to be a representation, and (3) we are perfectly capable of representing ourselves (e.g., recounting what we said from earlier, reenacting what we did earlier), then (4) the incarnation would simply be God’s representing Godself (if that is a word).
For God to act as an image of Godself would just be for God to be human, and surely no one would want to deny that God can represent Godself. Furthermore, when God represents Godself, God would be simultaneously human and divine (human insofar as God is the representation, and divine insofar as God is what is represented), just as we do not cease to be ourselves when we are representing ourselves.
Even the time/eternity puzzle is largely solved by this approach. When we represent ourselves by reenacting something we did earlier, we are acting in the moving present as an image of what is fixed and unchanging in the past. We are the same person in both times (both the present and the past), and yet one is properly temporal, and the other is something more like the eternal. When God represents Godself, therefore, we would expect God-qua-representation to be in time and God-qua-represented to be something more permanent, unchanging, or eternal.
I am assuming, in the foregoing, that to be an image of God is to be human, just as to be a human is to be an image of God. Otherwise, it would not necessarily be the case that God would automatically become human/incarnate whenever God represented Godself. Rather, God’s representing Godself in the form of a human, rather than in some other representational form, would be a choice God would have to make (just as we have to choose whether to represent our past selves by describing what we did, or by reenacting what we did). But even still, there would be nothing illogical or mysterious about the Incarnation. It would just be an act of God’s deliberate self-representation.
(My thinking here is significantly inspired by Robert Sokolowski’s discussion of the various types of images in, “Picturing,” in Pictures, Quotations, and Distinctions: Fourteen Essays in Phenomenology