Good vs. Evil Quotes in The Maze of Bones (The 39 Clues)

How we cite our quotes: (Chapter.Paragraph)

Quote #10

"A fire. [...] Like Grace's mansion. Like what happened to our parents. We haven't changed in all these centuries. We're still trying to destroy each other." (17.59)

Evil seems to be an endless cycle that's hard to break. It seems that people more often "fall from Grace" (pun intended) than they go the other way. Does evil always win out in the end?