The Church of Scientology has long been a controversial institution among both the religious community and entertainment business. But the latest documentary from Oscar-winning director Alex Gibney, “Going Clear: Scientology and the Prison of Belief,” explores the secrets of the organization through interviews with former high-ranking officials and former members in a way never seen before. Based on the 2013 book of the same name by Lawrence Wright, “Going Clear” not only exposes details about Scientology but also serves as an in-depth explainer for those unfamiliar with the group.