The novel remains relevant today, both in its treatment of a specific concern for equal treatment under the law in its more general moral message about the nature of prejudice and in its larger themes.
The novel explores broad themes that are relevant today and which will always be relevant. We can see this in many responses to the novel, as the book has been described as:
A regional novel dealing with universal themes of tolerance, courage, compassion, and justice...
More specifically, Harper Lee's novel presents an emphatic moral message regarding the dangers of prejudice. This is true on several levels in the novel. The example of Tom Robinson's trial is clearly expressive of ideas of legal injustice stemming from prevalent cultural biases.
This issue comprises a considerable portion of the text of the novel as well as the novel's purport.
Comprising the main portion of the book's examination of racism and its effects are the underlying themes of prejudice vs. tolerance: how people feel about and respond to differences in others.
In addition to race, class-based prejudice is also explored in the novel. The dangers of social isolation and subsequent criminal (and pathological) behavior are fully on display in the characters of Bob and Mayella Ewell.
These issues, as they express the dangers of entrenched cultural biases, remain relevant to our world today, which continues to be characterized by certain biases and intolerance.
In regards to equal treatment under the law, the novel remains poignantly relevant. Though there is widespread agreement that progress has been made regarding social justice for minorities, many scholars and social justice advocates point to a continuing and troubling trend in racially biased conviction rates and imposed penalties.
Sentencing reform is a topic of concern for the US government as well as social justice advocates today. The question of fair (or unfair) sentencing, beyond the initial wrongful verdict of the Tom Robinson case, is discussed in Lee's novel and the death penalty is questioned.
Jem, in particular, questions the application of the death penalty to Robinson, a man who is clearly innocent in the first place, and who was never accused of killing anyone.
Justice, as a concept, is given a figurative trial of its own in this way in Harper Lee's novel. The book continues to offer a relevant commentary on justice, prejudice, and the legal system, and also presents a figure of hope and integrity in precisely these contexts.
Atticus Finch stands as en example of a person dedicated to see that justice is done, regardless of entrenched and systematic biases.
When he takes on Tom Robinson’s case, he is determined to do all he can to defend him, even though he knows Tom’s case is all but hopeless – he is a black man on trial in a system which has already judged him.