Photo by Scala/Art Resource, N.Y.

ON THE COVER: St. Peter, nailed to a cross, is raised upside-down by his Roman executioners in this painting by the Italian artist Michelangelo Caravaggio (1573–1610), from the church of Santa Maria del Popolo in Rome. The apostle asked to be crucified in this unusual manner because, according to Jerome, “he was unworthy to be crucified in the same manner as his Lord.” In “Peter: How a Flawed Disciple Became Jesus’ Successor on Earth,” Pheme Perkins examines the life of the apostle, from his origins in Bethsaida and Capernaum on the Sea of Galilee to his growing stature in the church after Jesus’ death.