In Harper Lee's novel 'To Kill a Mockingbird', the character of Mr. Ewell is portrayed as a man with a prejudiced perception towards black people, considering them lower than white people. His anger and desire for revenge stems from Atticus Finch's successful defense of Tom Robinson, an innocent black man accused of rape. Scout, the daughter of Atticus Finch, tries to convince Mr. Ewell to change his perception and treat everyone with justice and respect. She emphasizes that pain should not be compensated by inflicting more pain, but rather by spreading joy and happiness. The novel highlights the importance of ensuring justice for all citizens, regardless of their race, gender, religion, or caste.