I think part of what made Star Wars Episode III better than the last two films was that it returned to the spiritual principals that made the original 1977 so good. The original introduced the Force which was a very Toaist and eastern concept. Combined with historical archetypes and lots of action adventure, this film found that rare recipe of both teaching and entertaining its audience.
There are new lessons in Episode III and they are so congruent with the Eastern spiritual concepts that I've been studying that I could write an entire essay or term paper on how many different spiritual philosophies and Eastern religions that Revenge of the Sith borrowed from.
One of the primary lessons was attachment. Part of Anakin's undoing was his attachment to Padme. At some point he stopped really loving her and she became a possession of sorts. Perhaps the idea was that losing his mother was so traumatic that he developed a need to hang on to his new love with a fierceness that was more desperate than romantic. Somehow Padme become secondary to his need to not feel that loss again. That was evident when he was strangling her. He couldn't handle the idea of her leaving him or rejecting him, it would bring up the pain and trauma from his past just as surely as her death would.
Detachment is one of the foundations of many Easter philosophies and I remember finding it in Taoism, Hinduism, Sikhism, Buddhism, etc. And not just attachment to things or people, but to ideas. Even being attached to your own ideas and opinions can effect your life dramatically. Evaluating the republic as good or evil was just as much of an attachment as Anakin's need to control Padme's presence in his life.
Yoda tried to convince Anakin that the death of his loved one was not a bad thing. He spoke of a concept of immortality that is a constant in most major Eastern religions. This wasn't a comfort to Anakin. He was too attached to her at that point to want anything other than control of her destiny.
The consequences of fear were also addressed in this movie. There is a philosophy that runs through many Easter religions that addresses the power of the mind and the ability to manifest. Whatever you give the most energy to in your mind can literally come to pass. So if you spend enough time afraid of something, it most likely will happen. This film illustrated that concept as Anakin slowly let his fears run his life. The fear of losing Padme was so great. But the path that fear took him on was actually instrumental in her eventual death. A perfect illustration of how we eventually manifest into reality the situations and things we fear.
I'm sure the spiritual ideas Lucas introduced in the original and first Star Wars film were a reflection of his own. And I think over the decades he must have matured spiritually and addressed these issues in his own life. It was a joy to see the ideas and lessons also mature in his film. It was not just entertaining on a visual level. It was a reminder of the spiritual laws and philosophies that govern my own life and how powerful you can be when you practice a life free of fear and attachment and how much you can hurt and destroy when you give in to them. I think we all have life situations that we judge as bad just as Anakin judged the republic. I think we all have some one or something in our life that we fear losing or happening. These philosophies are universal to us all.