(Metaphysics of Eucatastrophe, part 1)
The previous post suggested that the comparative absence of the Creator throughout Tolkien’s mythical history in some ways is consistent rather than contrary to how Yahweh is portrayed throughout Scripture. Even so, on the narrative and historical level of Tolkien’s mythology Eru is not nearly as aloof as some readers seem to have assumed. In the Ainulindalë, for example, after promulgating the first theme to the Ainur and inviting them to develop it as they see fit, Ilúvatar continues to contribute a great deal to the Music, especially in redirecting it in response to the corruptions introduced by Melkor, contributions which anticipate and correspond to Ilúvatar’s later direct involvement in human history. As Tolkien explains in one place the significance of this involvement of Ilúvatar,
The Creator did not hold himself aloof. He introduced new themes into the original design, which might therefore be unforeseen by many of the spirits in realization; there were also unforeseeable events (that is happenings which not even a complete knowledge of the past could predict).
Of the first kind and the chief was the theme of the incarnate intelligences, Elves and Men… Beings other than the Spirits, of less “stature,” and yet of the same order. (L 260)
Corresponding to the “second theme” introduced by Ilúvatar in the Music is the part of world-history containing the creation and consequent free choices of the “incarnate intelligences” of Elves and Men, beings in whose making the Valar had no part. In addition to this, however, Tolkien alludes to other “unforeseeable events (that is happenings which not even a complete knowledge of the past could predict),” an apparent reference to those miraculous events in Middle-earth’s history which transcend the natural order, events which Tolkien says elsewhere that not even the Valar, for all their magnificent power, are able to perform. As Tolkien clarifies in another place, although the Valar may be the “immediate authorities” in the world,
the One retains all ultimate authority, and (or so it seems as viewed in serial time) reserves the right to intrude the finger of God into the story: that is to produce realities which could not be deduced even from a complete knowledge of the previous past, but which being real become part of the effective past for all subsequent time (a possible definition of a “miracle”). According to the fable Elves and Men were the first of these intrusions, made indeed while the “story” was still only a story and not “realized”; they were not therefore in any sense conceived or made by the gods, the Valar, and were called the Eruhíni or “Children of God,” and were for the Valar an incalculable element: that is they were rational creatures of free will in regard to God, of the same historical rank as the Valar, though of far smaller spiritual and intellectual power and status. (235-6)
The image of Eru “intrud[ing] the finger of God in to the story” is alluded to in The Silmarillion itself when it said how, in a vision, the Valar Manwë “saw that all was upheld by the hand of Ilúvatar; and the hand entered in, and from it came forth many wonders that had until then been hidden from him in the hearts of the Ainur” (S 46). The “hand” of Eru, in other words, is always immanently present (at the “metaphysical level,” as I have termed it), “upholding” the world in its very being and in every particular, while the “finger” of Ilúvatar, we might say, signifies those moments (at the “historical” or “narrative level”) when Eru further deigns to make his unfailing presence manifest in an unmistakable way, by specially “intruding” into the story and interrupting or redirecting the natural course of events. What Tolkien refers to as Eru’s “absence,” therefore, is in fact a feigned absence whereby he and Tolkien as author create the historical and literary conditions for an even more radical display of his immanent presence. Providing as he does this scene toward the beginning of his legendarium (which also, by my reckoning, is the last time we see Ilúvatar give a direct address in The Silmarillion), I submit that part of what Tolkien is doing here is providing his reader with the necessary metaphysical framework and hermeneutic for rightly interpreting the subsequent, less theologically explicit yet still theologically significant portions of his mythology.
 As Thomas Fornet-Ponse describes this passage, it is an expression of “Eru’s sovereignty and his creatio continua…” Fornet-Ponse, “Freedom and Providence as Anti-Modern Elements,” 181.