Martin Luther: The Man Who Rediscovered God and Changed the World. Eric Metaxas is an excellent writer of biographies (William Wilberforce, Dietrich Bonhoeffer). This new book will be published October 3. https://www.amazon.com/Martin-Luther-Rediscovered-Changed-World/dp/110198001X/ref=sr_1_1?s=books&ie=UTF8&qid=1504618986&sr=1-1&keywords=eric+metaxas