Book excerpt: To mark the 500th anniversary of the Protestant Reformation, Paul Hacker’s landmark study Faith in Luther: Martin Luther and the Origin of Anthropocentric Religion appears now in a new English edition. Pope Emeritus Benedict XVI, in his final memoir in 2016, remembers Paul Hacker as “a great master, someone with an unbelievably broad education, someone who knew the Fathers, knew Luther, and had mastered the whole history of Indian religion from scratch. What he wrote always had something new about it, he always went right to the bottom of things.” No doubt one of the “things” he was referring to was Martin Luther’s view of faith, which Hacker explores in this text. A unique contribution to ecumenical studies, Faith in Luther engages the primary texts of Luther, assessing them for how they reveal Luther’s novel conception of faith and how the development of “reflexive faith” impacted Luther’s spirituality and theology—and the world.