In our present age in which apostolic Christianity is a foreign notion to many Christians, it is of little wonder that many of the beliefs of our ancient fathers have been deemed outdated, including the importance of fasting. By exploring the Holy Scriptures, patristics, Christian tradition, and personal experience, Lutheran seminary professor Harold Ristau seeks to answer the question Why fast? Through this concise examination of a historic Christian practice, which is as rich with meaning today as it was in antiquity, the reader is left with a deepened appreciation for Christian fasting. Ristau’s lively reflections on the relevance of fasting for catechesis, evangelism, and spiritual warfare fill the soul with great consolation. After all, our Lord Jesus’ words–when you fast–presume that this vital discipline is already happening, and perhaps without you even knowing it.