This popular novel by Judy Blume is perhaps one of the most influential novels on what we now refer to as the "young adult" genre. The title character, twelve-year old Margaret, is the primary narrator and frequently begins each chapter with the question in the title. Margaret asks God for help navigating the various problems in her life, one of which is deciding which religion she wishes to practice. Her mother is Christian and her father is Jewish, but both parents are ambivalent about their own practices and want Margaret to choose for herself.
As the story opens Margaret moves to a new town where she is worried about making friends at her new school. She makes three friends fairly quickly and the four girls form a club and spend a great deal of time together. All four of them are obsessed with issues of impending puberty, with one girl, Nancy, maturing somewhat faster than the others socially. In particular each of the four girls is anxious to start her first menstrual period, and to receive their first kiss from a boy. As Margaret and her friends begin to experiment and explore, their trust and loyalty is tested, and Margaret's frequent conversations with God also reach a crisis point when her prayers apparently go unanswered.
Margaret's main lesson has to do with becoming more self-reliant. She realizes she must make her own decisions and solve her own problems, partly as a result of finding her friends to be somewhat unreliable. In realizing she must become more independent, she also decides that talking to God may become a less frequent occurrence. In other words, the novel describes the type of self-actualization that can and should be part of the transition into early adulthood.