Following up on my previous message about Teshuva (repentance) in Harry Potter and the Deathly Hallows, a commenter wrote that I had left out Percy. Big omission! Percy is one of the most notable examples of teshuva in the book.
(Note, by the way, that I don't mean below to base moral lessons on characters as if they really exist. Yes, the books are fiction. But I believe that J. K. Rowling wrote them with a keen eye for human psychology, and that we can use the characters to explore moral lessons based on the way that G-d has built human psychology.)
In the Yom Kippur vidui (confession) service, we repeatedly refer to mistakes that we made because of "Timhon Levav," confusion of the heart, and "kashyut oref," usually translated as stubbornness. The idea in these two confessions, I think, is that people have a tendency to become very invested in what we think is true, basing our actions on huge sets of facts that follow, or that we think follow, from a small set of beliefs. Since our actions are based on our entire belief systems, it's very hard to admit that we've made a mistake, since it would require us to reexamine everything we believe.
But this is the lesson of Percy. Even after years of sticking with our belief systems, believing that we're right, we still have the power to reexamine our belief systems to find things that we want to change.
In the final few Harry Potter books, Percy stuck to his beliefs, since they were all predicated on a view of the world that he was convinced was right. But once he was really pushed to think about it, for his own internal reasons and not because of outside pressure, the house of cards that he was believing in fell to the ground. In the end, he not only changed sides in the fight against Voldemort, but changed all those aspects of his life that were built on that house of cards.
It's also important to note, by the way, that Percy couldn't make this change when pushed by others. He had to realize it himself and make the changes to his beliefs from within. This is because the house of cards of beliefs could answer the claims that others were making. He could only realize the mistakes when he was forced in his own mind to think about the underpinnings of his beliefs. I think that this is worth thinking about for all parents, teachers, and others who try to help others improve -- core changes often need to come from within.
Ultimately, I think that the type of teshuva exemplified by Percy is what we're meant to do during the month leading up to Rosh HaShana, and during the time period between Rosh HaShana and Yom Kippur. As I quoted in the Harry Potter and Torah chapter on Destiny and Decisions, the midrash tells us that if we repent properly during the time between Rosh HaShana and Yom Kippur, G-d will credit us on Yom Kippur as if we were entirely new people.
NOTE that I posted a follow-up message, with more elaboration, here: