Hour 2: What prompts a person to commit their life to charity and service and how can common human emotions get in the way of that devotion? We’ll find out this hour with Mary Johnson who served for twenty years as a sister in the Missionaries of Charity. Her new book is “An Unquenchable Thirst: Following Mother Teresa in Search of Love, Service, and an Authentic Life” (Spiegel & Grau, 2011).