Many people would be surprised to hear that a playful attitude towards God and the world lies at the heart of Christian faith. Traditionally Christians have focused on the serious responsibilities of service, sacrifice, and commitment. But the prophets say that the future kingdom is full of people laughing and playing, which has implications for Christians who are called to live out the future kingdom in the present. Play is not trivial or secondary to work and service—only a playful way of living does justice to the seriousness of life! Play is the essential and ultimate form of relationship with God, which is why Jesus told people to learn from children. Indeed, a playful attitude is an important part of all significant relationships. This book explores grace, faith, love, worship, redemption, and the kingdom from the perspective of a playful attitude. It describes how to create a "play ethic" to match the "work ethic" and discusses play as a virtue, Aquinas's warning against the sin of not playing enough, and Bonhoeffer's claim that in a world of pain it is only the Christian who can truly play.