On 31 October 1517, Martin Luther posted his ninety-five theses on the castle church door in Wittenberg. More than any other event, this has the best claim to be the starting gun that set the Reformation in motion. Five hundred years later, the Reformation still has important things to say. In this clear, incisive and accessible survey, Michael Reeves and Tim Chester show how the Reformation helps us answer questions like: How do we know what's true? Can we truly know God? How does God speak? What's wrong with us? How can we be saved? Who am I? That many people today find the Reformation strange and remote exposes our preoccupation with this material world and this momentary life. If there is a world beyond this world, and a life beyond this life, then it doesn't seem to matter very much to us. At its heart, the Reformation was a dispute about how we know God and how we can be right with him. At stake was our eternal future - and it still is.