Christianity is not about rituals but changed hearts. In the prophetic tradition of Dietrich Bonhoeffer, Eric Metaxas calls slumbering Christians to battle. Picking up where he left off in his electrifying Letter to the American Church, Eric Metaxas renews and deepens his call to believers not to "practice" their faith but to live it--heroically and with joy. Invoking famous but misunderstood words of Dietrich Bonhoeffer,...