I cannot emphasise enough just how great this book is. Dostoevsky introduces a set of characters, and through their completely believable and realistic interactions, expresses powerful, mystical messages. In essence, the story is about a young, intelligent former student, Raskolnikov (similar to Raskol, schism), who by cold, unemotional thought arrives at a sort of nihilism, and even goes so far as to thinking that an "extraordinary person" is justified in taking away a useless, harmful life for the greater good, and then, partially out of an effort to prove that he is such as person, commits a murder which he feels fits this program. At the same time, there is seething conflict inside him; the compassionate, loving side of his personality is revolting against these horrible thoughts. As Razumihin remarks, Raskolnikov is two people living in the same body. In a sense, Raskolnikov's original idea is correct; there is no harm done in removing pure, harmful evil, but one of Dostoevsky's principal messages in this novel is that there is no such thing as a purely harmful individual; Dostoevsky accomplishes this goal by presenting the character of an old pawn broker and her half-sister, Lizaveta. Through Raskolnikov's eyes, all good characteristics are placed in Lizaveta, and all that is evil is placed in the pawn broker; hence Raskolnikov feels justified in killing the pawn broker, but really it should come as no surprise that he ends up ....
I'd type more but I don't want to spoil the book any further .