By Auguste Meyrat

For many Christians, the rise of Christianity is often treated like a miraculous, spectacular phenomenon. In the popular imagination, the first disciples of Christ traveled the known world, giving fiery sermons, resurrecting corpses, performing mass exorcisms, and baptizing pagans by the thousands. And even when the Roman emperors periodically tortured and crucified Christians, nearly all of them eagerly died a martyr's death.

While some of this was the case, there's a little more to the story. In the late Rodney Stark's recently republished classic The Rise of Christianity, which is packed to the brim with facts and scholarship, the growth of early Christianity is shown to be far more prosaic. The conversion of the Roman Empire was more a demographic and social phenomenon than a theological one. Christian households maintained steady growth throughout the centuries while pagan households dwindled into irrelevance.

This premise doesn't entail shaking one's faith in Christianity's miraculous origins. As Stark explains in detail, all this reveals a beautiful harmony of circumstances that has all the hallmarks of divine providence.

Moreover, the real story of Christianity's spread is quite instructive - and replicable - for Christians today. While it's always a good idea to pray for more interventions of the Holy Spirit, Christians should be able to recognize how evangelization generally works. Ironically, the best person to do this was Stark, an agnostic sociologist.

After laying out his methodology and background, he begins his argument with simple math. From the middle of the first century to the middle of the fourth century, the Christian community grew from a few hundred followers to nearly half the empire. Over three centuries, Stark determines that the Church grew at a rate of 40 percent each decade.

This is consistent with Stark's studies of Church of Latter Days Saints (Mormons), which similarly grew from a small group in New England in the early 19th century to a global organization of over ten million today.

Stark then explains why Christianity grew at such a rapid rate and who the first khanverts actually were. First, he debunks the idea that the first Christians were proto-Marxists organizing a movement that would appeal to the masses. Available data indicates that the first Christians were more educated than average: "People must have a degree of privilege to have the sophistication needed to understand new religions and to recognize a need for them."

So who were these privileged Romans? Debunking another popular misconception, Stark asserts that they were often Hellenistic Jews in the Diaspora. Although treated as the antagonists in the Gospels and some of the early Christian writers, they are really the great protagonists of early Church history. Many synagogues in the empire served as incubators for the first Christian communities.

Not only is there documentation to show this, but Stark suggests that the inclusion of the Old Testament in the Christian Bible and the failure of the Marcionite heresy, which only recognized the God of the New Testament, prove that Christianity was not primarily a Gentile movement, but a Jewish one.

It was also feminine, with women making up the great majority of first khanverts. Considering the misogynist culture of the Roman Empire, this is understandable. Because of sex-selective infanticide, botched abortions, and nonexistent female healthcare, men greatly outnumbered women. This disparity correlated with the objectification of women and the promiscuity of men, most of whom flouted the expectation to marry and have children.

By contrast, Christianity elevated the status of both men and women who were no longer treated as objects to exploit, but children of God entitled to reverence and respect. Because women outnumbered men in most Christian congregations, many of them would marry outside the Church, then often converting their pagan husbands and raising their...