"My Father, I put myself in your hands", wrote Charles de Foucauld in his journal. "Whatever you make of me, I thank you, I am ready for everything, I accept everything, I thank you for everything." When he was killed by bandits in 1916, the French aristocrat-turned-monk was virtually unknown. Over the course of a century, however, the radiance of Foucauld's hidden life has spread more and more, and the Church now recognizes him as a saint. His...