[Dakêsîntrah]

So no, he is not housed in essentially the same body; on the contrary, this presents a fundamental change, not just a hair tint and a romp through Galadriel's closet. Gandalf's physical manifestation has been divinely altered, so much so that he must drape himself again in his gray rags to hide his luminescence.

I concede that is the case from the text now. However, the physical *form of Man was not altered dramatically. Of course he was light "as a feather," and of course against his new and divinely incarnated sorcery skills, the Fellowship's Middle Earth weapons would be useless.

This still does not mean a spirit neither living or dead can be hindered with an enchanted sword versus Gandalf - still in the fleshly form of Man.

I agree with you, but I see Tolkien's Gandalf differently than you, perhaps because I am so entrenched in Christian theology.

In Christianity, Jesus is clearly said to be God himself, come to earth in human form, as one of the Trinity. He is not a created being, but was in existence for eternity. In Arda, there is no Trinity - there is only Eru, who is the sole god. He created the Ainur, of whom some are Valar and Maiar. These may be called "gods" by the Children, but they are clearly intended to be angelic creatures. Gandalf is one of the Maiar.

Of course there are various sects of Christianity, and I am sure Tolkien was aware of Gnosticism - a form of Christianity that went all the way back to the time of the apostles or beyond. I know I am probably going on a rabbit trail here, but whether or not Tolkien intended it, some of his Middle Earth "theology" has its roots in his Catholic orthodoxy, and then I see other concepts which have root in Christian Gnosticism. I'm surprised nobody has dealt with Tolkien's Gnostic parallels before, as far as I am aware of. Gnosticism was Roman Catholicism's ancient foe, and I am sure Tolkien came across these watershed traditions during his medieval studies - it is a thing that pervades not only church history, but secular as well.

So, in some Gnostic theology, Jesus is not God, and the Trinity is not really a Trinity, rather manifestations of the Godhead Himself. Much like the Eldar who seemed to emanate from Eru. And of course, as Jesus was an emanation, he was also a created being who came to earth in the guise of a man, as a Messenger. He was not the only Messenger to bring the Light in a Dark World. There were notably four other sages.

The one true God of the ancient Pneumatics was the Sumerian Anu - a close resemblance to the name Eru. Anu and Eru are able to manifest themselves through emanations - so I believe (all conjecture) that Olórin was some sort of manifestation of Eru Himself. Once again, nobody seems to talk about Tolkien and his parallels to even Sumerian myth, but I wouldn't be surprised to find out he knew quite a deal of it.

Gandalf's sacrifice was, I think, incidental. He happened to be in the wrong place at the wrong time

If Olórin is an emanation of Eru, I cannot agree with "he happened to be in the wrong place at the wrong time." I see God's Will as all Sovereign. Whatever happens, whether tragedy or evil triumphs, it is still the Will of the God.

Best Regards