I like your description of Luther’s idea about God simultaneously revealing and hiding himself. I would only add one thing: this idea itself has deep roots in the Thomist tradition (and perhaps earlier; I’ve never comprehensively traced the progression of this idea). For one obvious example, check the lyrics to the Angelic Doctor’s Eucharistic hymn “Adoro te devote.” There Thomas contemplates the “latens Deitas” (“hidden Deity”) that deceives sight, touch and taste; hearing alone is to be believed by faith. It is in Christ’s absolute, true, and Real Presence that he seems absent. Going further, the contrast is made between the Eucharist and the Cross; the first, Thomas says, hides the humanity of Christ, while the latter hides his Divinity–yet he confesses the truth of both in an inseparable union. In the final stanza Thomas contrasts the now and the not-yet by connecting the act of gazing upon the Eucharist (now we see in part) with the eschatological gaze of the Beatific Vision (then in full).

And this doesn’t even begin to consider the ideas of the mystics who emphasize God’s deepest and most immediate presence in those times when the Christian feels as though he is farthest removed from God. God seems distant and the dryness sets in; right, they say–it is often precisely in the midst of this sense of absence and loss that the most spiritual progress toward union with Christ is made.

Some other time, could you please say more about *how* Luther’s view of God’s incomprehensibility and self-revelation relate to his ‘rejection of all philosophical speculations on how Christ is physically present’? I think I get what you’re saying, but I don’t see how the one necessarily follows from the other (as seen in my quick example from Aquinas). As I’m sure you know, medieval theological reflection is full of this kind of reveling in paradox. It is good to be reminded of this in regard to Luther. Thanks again for your contribution, and I look forward to more on this!