Anakin…exists relative to the state of the galaxy. He is not Luke, he is not the youth of western literature on a journey; that is Luke’s role. Anakin’s role is that of the demi-god of Greek and Roman origin. When Anakin rises, the galaxy rises with him, when Anakin is in turmoil, the galaxy is in turmoil, when Anakin falls, so falls the galaxy. Anakin is intrinsic to the galaxy because Anakin, like so many other mythological demi-gods, is an avatar for the gods or, in the case of Star Wars, the Force. Regardless of any one person’s views on the Force (which are extremely disparate and widely varied, so we won’t broach that subject here), this fact is indisputable. Anakin, as the Chosen One who will “bring balance to the Force”, is its avatar. When Anakin is claimed by the Dark, the Jedi Order’s zenith is reached, the Balance is tipped, and the Order descends into darkness with Anakin, just as his return also signals theirs.-- ‘STAR WARS: The Creation of a Modern Myth: Cultural Influence, Fan Response and the Impact of Literary Archetypes on Saga Perception’
The title ‘Return of the Jedi’ doesn’t just reference Luke becoming a Jedi, but Anakin’s return to the Light, and with it, the ability for the Jedi Order to once more flourish. In this he is much like Beowulf, when the Geatish hero sacrifices himself to defeat the dragon at the end of the epic poem. Failure would spell ultimate destruction for Beowulf’s people and country, just as, had Anakin failed to destroy the Emperor, the Jedi and the galaxy would truly have been wiped out. Anakin himself has to die, however, because he is what tips the scales. Once he dies and becomes one with the Force, only then is balance restored."
This right here is absolutely fundamental to understanding the entire purpose of the Skywalker saga, as Lucas so painstakingly told it. The destruction of the old Jedi Order that had ‘lost its way’ and forgotten its true role in the galaxy, and the founding of the New, heralded by Anakin’s return to the Light, and Luke’s essential role in reminding him—and us all—of what it means to be a True Jedi.