If you no longer “believe in God,” the Supreme Being of classical theology, or you never did in the first place, is there anything you still ought to believe, anything you should cherish unconditionally, no matter what? In this lively and accessible book, addressed to believers, “recovering” believers, disbelievers, nonbelievers, and “nones” alike—to anyone in search of what they really do believe—the acclaimed philosopher and theologian John D. Caputo seeks out what there is to believe, with or without religion. Writing in a lucid and witty style, Caputo offers a bold account of a “radical theology” that is anything but what the word theology suggests to most people. His point of departure is autobiographical, describing growing up in the world of pre-Vatican II Catholicism, serving as an altar boy, and spending four years in a Catholic religious order after high school. Caputo places Augustine’s Confessions, Tillich’s Dynamics of Faith, and Jacques Derrida and postmodern theory in conversation in the service of what he calls the “mystical sense of life.” He argues that radical theology is not simply an academic exercise but describes a concrete practice immediately relevant to the daily lives of believers and nonbelievers alike. What to Believe? is an engaging introduction to radical theology for all readers curious about what religion can mean today.