What passages in Harper Lee's To Kill a Mockingbird show the coexistence of good and evil?

The central theme in Harper Lee's To Kill a Mockingbird concerns human nature. Lee shows us that human nature is made up of both good and evil characteristics, and she does so by frequently juxtaposing good and evil. As Scout and Jem grow up, they shed their innocent childhood belief that the world is made up of primarily good people and come to realize the evil that exists in the world.

One example of Lee juxtaposing good with evil can be seen in Mrs. Henry Lafayette Dubose. All the neighborhood children stay as far away from her house as they possibly can because they see her as being the meanest old lady in existence. However, as Scout and Jem get older, they begin wanting to go into the business district of Maycomb, requiring them to walk past Mrs. Dubose's house. They particularly begin walking up to the post office each day to meet Atticus on his way home from work. Each time they pass Mrs. Dubose's house, she yells cruel and critical insults at the children. The children receive the worst insult from her when she one day says, "Your father's no better than the the niggers and trash he works for!" (Ch. 11). The insult is enough to infuriate Jem to the point that he destroys every camellia flower in her garden leading up to what seems to be his punishment of needing to read to her every day. In reality, Jem's reading to her every day is not a punishment since she asked him because she sincerely needed his help, and Atticus says he would have asked him to do it regardless.

What is surprising is that, despite her insults and racist beliefs, beliefs Atticus thoroughly disagrees with, Atticus strives to be kind to her each time he sees her, saying, "Good evening, Mrs Dubose! You look like a picture this evening." Later, after her death, we learn that Atticus felt genuine admiration for her because of her courage. Atticus explains to his children that she was a morphine addict and, though her illness made the use of morphine understandable, she decided she would not die a morphine addict and had asked Jem to read to her to distract her as she underwent her withdrawal symptoms. As Atticus phrases it, he saw her as "the bravest person [he] ever knew" because she made sure she "died beholden to nothing and nobody" (Ch. 11).

Hence, as we can see, one way in which Lee juxtaposes good and evil is through Mrs. Dubose. Though Mrs. Dubose had what could be considered evil thoughts and ways, she could also be considered a good person due to her personal strength and courage.