Crime and Punishment is very interested in the idea of "judgment" – judgment of self, of others, judgment of and by society, and judgment of and by religion. The novel asks us to judge not only the characters, but also the characters' judgments of each other. The prize that we and the characters seek as we travel through this maze of judgment and judging is "justice," or, in plain language, "fairness." Whether or not that prize is realized within or at the end of the novel is a question you might want to ask as you read.
Because Raskolnikov learns how to become a non-violent member of society while in prison, Crime and Punishment argues that prison is an important element of social justice.
The characters who stand by Raskolnikov even after his crime is known demonstrate that love and friendship can work together with judgment to help bring justice.