To Kill A Mockingbird has many instances of figurative language, beginning with the title. Atticus Finch, the main character, reminds his children that "it's a sin to kill a mockingbird," and the reader understands this from a metaphorical perspective because, as will be revealed in the story, prejudice and discrimination ruin relationships and lives. Mockingbirds "don't do one thing but make music for us to enjoy," explains Miss Maudie to Scout, who is puzzled by her father's talk of sin in the context of mockingbirds, the real sin being that against an innocent man, Tom Robinson whom the mockingbird represents.
Boo Radley is also a victim in To Kill A Mockingbird because, after making some bad decisions, he is confined to his home for many years. His father thought that "anything that's a pleasure is a sin," and this metaphor is used to reinforce the destructiveness of relationships based on a need to be socially accepted in a socially unjust environment. Boo Radley is assumed to be some sort of a monster based on preconceptions and rumor.
Atticus, as ever, wants his children to recognize the rights of others to their opinions and to never judge anyone until they can, "climb into his skin and walk around in it." Scout is very upset because her teacher does not appreciate her abilities and the fact that she had learned to read before starting school but Atticus wants her to understand that her teacher is new to the area and therefore, the young Scout must make allowances for her.
"A person's conscience" is personified (attributing human qualities directly to the conscience which, in itself is only one aspect of a person) when Atticus talks of his reasons for taking Tom's case. He says:
"The one thing that doesn't abide by majority rule is a person's conscience"
suggesting that the conscience can make decisions independently. Atticus has to "live with myself." This usage supports the issue of moral blindness that pervades Maycomb County.
Atticus "one-shot Finch" surprises his children when they learn that he has a depth of character which had previously escaped them. He has not told the children about his abilities handling a gun because, as he says,
"I wanted you to see what real courage is, instead of getting the idea that courage is a man with a gun in his hand. It's when you know that you're licked before you begin (metaphor) but you begin anyway and you see it through no matter what. You rarely win, but sometimes you do."
The use of personification ("courage is a man...") is a strong reminder to the reader that appearances can be deceiving and, much like the message from the "The Grey Ghost," which Atticus read to Scout, there is an overriding need to "finally see" people for what they really are.