Beginning with a quote from Diognetus, this study asks why Christians came to be described as a γένος. This book argues that 1 Peter provides original, provocative answers to Diognetus’ questions. This book argues that the description of believers’ ethnic identity in 2:9-10 is founded on the complex metaphor of divine regeneration and its familial entailments. Just as physical ethnic identities are established primarily by birth into a particular group, the Petrine author ascribes to believers a divine regeneration that ushers them into a new ethnic community. However, ethnic membership is not a matter of birth alone: it is a social construct that must be taught, negotiated, maintained, and defended. It process of socialization stretches from infancy to childhood and finally adulthood. This introduction then surveys previous scholarship on divine regeneration in 1 Peter and establishes the need for a new look at divine regeneration in 1 Peter.