Social scientist Rodney Stark did more than puzzle: he created a set of testable hypotheses and tried, via secondary literature (he reads no ancient language and disclaims any expertise in the traditional scholarship of early church history), to probe the key issues. Along the way, he uses contemporary social science findings from demography, the sociology of small groups, the psychology of conversion, medical statistics, and every other conceptual lever he could divine to create a compelling mosaic of findings, arrayed in discrete topical chapters (each of which had a former life as a scholarly article).

Others have pointed out, as does Stark himself, that his work is a strictly scientific enterprise: his own religious views are for himself. he is a sociologist of religion. He gives respectful attention to the historical record of the early church, which consists almost exclusively of the well-known testaments from the early church -New Testament accounts, non-canonic letters and gospels, and works by Eusebius, Tertullian, and their peers. But in the end, the "miracle" of the expansion of the early church seems explicable by a number of readily understandable facts and processes.

For example, the forty percent growth rate per decade from 30 CE to 300 CE, which arithmetically gets one from 40 converts to 6 million, seems virtually miraculous - until Stark compares this rate to the growth achieved by the Church of Jesus Christ of Latter-Day Saints - the Mormons - which in the past century has averaged just over 40 percent per decade. In separate chapters, Stark also sheds fresh light on the geographic spread of Christianity, the success - rather than the long presumed failure - of "mission to the Hebrews," the role of plagues and natural disasters as facilitators of the Christian mission, Christian conversion as an urban phenomenon, the comparative socioeconomic advantages of Christianity versus "paganism" in the "religious marketplace" of antiquity, and the "rationality" of martyrdom, the last of which contains more than a few startlingly relevant observations in the current context of terrorist martyrdom.

Throughout, the emphasis returns again and again to social networks - friends converting friends, wives converting husbands, former Jewish co-religionists converting other Jews as Christian churches establish themselves in the "Jewish Quarters" of Roman towns and cities, mercy-bound Christians staying to care for plague victims while pagans flee the pandemic.

Some chapters, needless to say, are less compelling than others. Stark's fascinating discussion the allure of Christianity to the wholly disenfranchised women of the Roman empire, and of the advantages conferred to women in the early church, stands at odds with persuasive accounts - say, those of Elaine Pagels in The Gnostic Gospels or Bart Ehrman in Lost Christianities - of the steady hostility toward the role of women in the church and in the canonic New Testament accounts.

This is a minor quibble. Stark has given us a necessary book - for believers, skeptics, pastors, and laypeople - that, in conception alone, is the stuff of genius. And - whipped cream on top - the author has serious journalistic chops, honed in a former life as a newspaperman, that make him that rare social scientist who can actually communicate his findings crystal-clearly to an intelligent reader. What results is a provocative, beautifully wrought book that sets a standard for contemporary exploration of a distant, thinly documented historical occurrence.

Church leaders and theologians would do well to read this book and ponder for themselves. For the thinking person who is open to arguments that actually use numbers in an intelligent way (no Bible Code here!), this is a book that offers insight into the mechanisms of church growth, the practical consequences of sexual immorality, and the positive effect of having a high value on women.