[leapofberen]

Before it gets too far long, my apologies. Going back to the original question, in my haste I think I confused the Themes of the First Music with the Second Music that (if I remember rightly) Men will play a part in, but it was not specified if the Eldar or even the Valar will participate though the Eldar believe Eru will not abandon them.

I agree with the line of thinking in the posts...my thoughts (conjecturing here) are that Eru seems to have tied himself forever to the Children in a way that he did not tie himself even to the Valar; rather the Valar forever tied themselves to the world for their love of the Children. The Children were something of an enigma even to the Valar, and up through the end of the Third Age I think we see what appears to be their apparent dis-involvement because they are not "seeing" prophetically as clearly as they once did, perhaps because the Themes of the Music are being fulfilled. As the age of Men approaches, it seems they become less and less involved. So like the Elves, who are destined to fade, the Valar essentially "fade" as well, as they and the Elves now reside (mostly) in the uttermost West. So comes the age of Men.

The Beren/Luthien them here is an excellent point in that Beren gave up his life for Luthien and Luthien for him, I suppose, in a way that (following with the Christian theme) does seem to foreshadow the eventual Incarnation alluded to by Finrod Felagund. That is, Eru, having forever tied himself to the Children out of love must go to all ends to eventually save them, even tying himself to mortality through death and resurrection (as Luthien tied herself to Beren, I suppose.) And that tie, specifically to men, seems to be:

1) mysterious and troublesome to even the Valar and the Eldar (at least I get that feeling in reading the Silmarillion.) It would be appropriate that Finrod Felagund would seem to understand the most about the future of Men (the possible incarnation of Eru) as he is the most compassionate and loving towards Men from the very beginning.

2) that mortals, though weak, seem to hold the key to defeating evil...ultimately, the Hobbits best demonstrate the power to overcome evil with good, the weak overcoming the strong. Where the might of the Noldor could not defeat Morgoth, nor even the Valar (fully) as it seems Morgoth "dispersed his power into the very matter of Arda," along come the Hobbits who ultimately defeat the last of Morgoth's incarnate print on Middle Earth. It does seem to foreshadow the Christian theme of God binding himself to Man (via the Incarnation) and defeating evil, not through power, but through the weakness of death (becoming mortal, weak.)

I know much of this is conjecture, but just writing out what I began to see in Tolkien's stories recently...