The Last Safe Place on Earth by Richard Peck

Todd has totally fallen for Laurel, his little sister Marnie’s babysitter. She is preppy, distant and completely mysterious. But when Marnie starts having bad dreams about evil and hellfire, Todd realizes that it’s because Laurel is filling Marnie’s head with her own special brand of Christian fundamentalism. Todd finds himself torn between his desire for Laurel and his distaste with her personal convictions. Things heat up even more when a local church group, of which Laurel’s mom is a member, pressure the school to remove certain books from the library. Todd starts thinking long and hard about his views on religion, censorship and individual responsibility. The implications and consequences of this novel will hurt your head (but in a good way).