Everything you need to understand or teach Waiting for the End of the World by Madison Smartt Bell.
The primary theme of this novel is the protagonist's struggle to discern good from evil and to choose the former while overcoming the latter. Initially Larkin appears to be truly the disinterested character, little concerned about self-preservation. He also claims to avoid involvement with others; however, he repeatedly attempts, usually with limited success, to rescue people in trouble, and as his repressed memory illustrates, he has tried — in one case, literally — to "break through" to people such as Karin and Sybil. Further, Larkin is drawn to fire; Arkady refers to his apocalyptic obsessions and fantasies. In fact, Larkin is obsessed with the question of redemption; as one of his demons insists, he believes that he possesses a great soul and so must also be a great sinner.
Certainly the issues of sin and redemption are central to this novel.