The old man in Fangorn who approaches Aragorn, Gimli and Legolas isn't Saruman but Gandalf, miraculously back from the dead.
Back, but also changed.
As Fleming Rutledge observes, and I agree, many readers have too quickly made Gandalf the Christ-figure of the story due to this resurrection event. But there is no single Christ-figure in the story, there is, rather, Christlikeness found across the many characters as the drama unfolds. Gandalf, Frodo, Sam, Aragorn, and the others, all step into the spotlight at points to display Christlike virtues or motifs. And Gandalf's return is one of those moments.
And yet, other than being back from the dead, there is little in Gandalf's return that echos the resurrection of Jesus. At this point in the story the battle against evil is really just starting to ramp up, touch and go from here on out, the whole enterprise precarious. Gandalf has been sent back not in final victory but to keep the fight from faltering. From here on out, there's a swiftness and urgency to all his actions. The battle isn't won with his return, the battle is engaged.
And so, I think Rutledge is right to see the return of Gandalf as less a resurrection event than a transfiguration:
"Mithrandir!" [Legolas] cried. "Mithrandir!"
"Well met, I say to you again, Legolas!" said the old man.
They all gazed at him. His hair was white as snow in the sunshine; and gleaming white was his robe; the eyes under his deep brows were bright, piercing as the rays of the sun; power was in his hand. Between wonder, joy, and fear they stood and found no words to say.
At last Aragorn stirred. "Gandalf!" he said. "Beyond all hope you return to us in our need! What veil was over my sight? Gandalf!" Gimli said nothing, but sank to his knees, shading his eyes.
This transfiguration echos the transfiguration of Jesus. But also, Rutledge points out, other transfigurations in the Bible, like Moses' face glowing before the people of Israel.
And the point, obviously, is that this story isn't simply a story of human actors (well, humans plus dwarves, hobbits, and all the other physical creatures of Middle Earth). The drama has a metaphysical backdrop that here breaks into the story. There are deep supernatural (if we can use that word) forces at work, and here, with the return and transfiguration of Gandalf, they make their most visible, dramatic, and decisive appearance. An in-breaking that can only be described as one of grace, impossible hope, and joy. As Aragorn says, "Beyond all hope you return to us in our need!"
