What are some quotes in Harper Lee's To Kill a Mockingbird that show the main conflict in the story?

There are two main quotes from Harper Lee's To Kill a Mockingbird that I'd like to focus on here. The first deals with loss of innocence, a main theme at the heart of the book's conflict, and the second deals with racism, the cause of the book's conflict.

Here's the first quote, which is spoken by Miss Maudie toward the beginning of the novel:

Mockingbirds don't do one thing but make music for us to...

There are two main quotes from Harper Lee's To Kill a Mockingbird that I'd like to focus on here. The first deals with loss of innocence, a main theme at the heart of the book's conflict, and the second deals with racism, the cause of the book's conflict.

Here's the first quote, which is spoken by Miss Maudie toward the beginning of the novel:

Mockingbirds don't do one thing but make music for us to enjoy. They don't eat up people's gardens, don't nest in corncribs, they don't do one thing but sing their hearts out for us. That's why it's a sin to kill a mockingbird. (94)

Here, Miss Maudie introduces the central symbol of the mockingbird. Basically, Lee uses the mockingbird to symbolize a state of innocence, while the act of killing one is a symbol for the destruction of this innocence. The destruction/loss of innocence is a central part of the book's conflict, as Jem and Scout gradually lose their innocence through their experience of the racism in their community.

Here's the second quote, which is spoken by Atticus during the trial:

... I would like to use my remaining time with you to remind you that this case is not a difficult one, it requires no minute sifting of complicated facts, but it does require you to be sure beyond all reasonable doubt as to the guilt of the defendant. To begin with, this case should never have come to trial. This case is as simple as black and white. (205)

In this quote, Atticus references the fact that it's quite clear that Tom Robinson is not actually guilty, and he was only brought to trial because he is a black man living in a racist community. As such, the quote highlights the main conflict of the story: the brutal, unjust oppression of racism. It is this conflict that ultimately destroys the innocence of Jem and Scout.