“Shaw returned on Tuesday, having been recalled for the pickup shot against black velvet, which Lucas supervised; the unmasked Vader would now appear as a “ghost” along with Yoda and Ben at the end.
Ironically, Kazanjian had changed his mind about this being such a good idea.
“I’d started thinking about it and I said to George, ‘Why? This guy—he’s like Hitler. He’s killed. He’s done all of these terrible things and now we’re saying he’s equal with Yoda and Obi-Wan, as if he’s gone to heaven or whatever.’
And George pointed at me, he was real close, and he says, ‘Isn’t that what your religion is all about?’ And, boy, that was like being slapped on the side of the face, because, yes, it is what my religion is all about.”

The Making of Return of the Jedi

this is a really interesting tidbit re: Anakin’s redemption.

(I’m assuming the religion in question is Christianity.)