Nietzsche was Wagner's biggest fan, you you might expect, eating up all the proto Germanic ubermensch themes. And then Wagner came out with this, his last and perhaps greatest opera. Nietzsche about had a fit at the Christian themes, and wrote the whole thing off.
As with much from Nietzsche, he was throwing the baby out with the bath water. Wagner's story is from what is perhaps the most interesting tale in all of Western Civilization: Gotfried von Strasbourg's 1210 A.D. story Parzifal. Gotfried, like all writers of his age took common stories that dated far, far back. Starting with something that would be familiar to listeners, the story teller would add depth and make the characters his own.
What Gotfried did was to create what was the first truly modern psychological view of Western Man (certainly this was Joseph Campbell's claim). It was one that synthesized Classical Greco-Roman, Christian, and native European Celtic and Germanic themes into what is unmistakeably modern Western thought.
Nietzsche, of course, hated the Christian aspects of spiritual rebirth. But the synthesis that comes from repeated failure leading ultimately - if we are lucky - to a breakthrough in our own realization of our lives, that is perhaps uniquely western. And quite appropriate for Easter.