What does baptism do to the baptized? Nothing? Something? In this study, Peter Leithart examines this single question of baptismal efficacy. He challenges several common but false assumptions about God, man, the church, salvation, and more that confuse discussions about baptism. He aims to offer a careful and simple discussion of all the central biblical texts that speak to us about baptism, the nature of signs and rites, the character of the church as the body of Christ, and the possibility of apostasy. In the end, the author urges us to face up to the wonderful conclusion that Scripture attributes an astonishing power to the initiation rite of baptism.