The supposed collapse of Roman civilization is still lamented more than 1,500 years later—and intertwined with this idea is the notion that a fledgling religion, Christianity, went from a persecuted fringe movement to an irresistible force that toppled the empire. The "intolerant zeal" of Christians, wrote Edward Gibbon, swept Rome's old gods away, and with them the structures that sustained Roman society.

Not so, argues Douglas Boin. Such tales are simply untrue to history, and ignore the most important fact of all: life in Rome never came to a dramatic stop. Instead, as Boin shows, a small minority movement rose to transform society—politically, religiously, and culturally—but it was a gradual process, one that happened in fits and starts over centuries. Drawing upon a decade of recent studies in history and archaeology, and on his own research, Boin opens up a wholly new window onto a period we thought we knew. His work is the first to describe how Christians navigated the complex world of social identity in terms of "passing" and "coming out." Many Christians lived in a dynamic middle ground. Their quiet success, as much as the clamor of martyrdom, was a powerful agent for change. With this insightful approach to the story of Christians in the Roman world, Douglas Boin rewrites, and rediscovers, the fascinating early history of a world faith.