Rodney Stark has been crunching the numbers on the spread of the Christian movement in its first century. He has examined data from 31 Roman cities that had populations of at least 30,000. Here are his findings on the spread of the Christian congregations.
1. Port cities tended to have Christian congregations sooner than inland cities.
Despite their reputation, Roman roads were still much inferior to boats for travel. Rome was a waterfront empire surrounding the Mediterranean. 64% of port cities had a church by the end of the first century while only 24% of inland cities had a church that soon.
2. The closer a city was to Jerusalem, the sooner a city had a Christian congregation.
Christianity’s base was Jerusalem until it was forced to move by the Jewish Revolt. Most cities (71%) within a thousand miles of Jerusalem by the year 100, compared with only one (7%) of the cities further away.
3. Hellenic cities (Greek language and culture) had Christian congregations sooner than did Roman cities.
In the first century far more Jews spoke Greek than Hebrew or Aramaic. When Paul stripped the Jewish prerequisite from Christianity, he not only made the faith open to Gentiles, but offered the Hellenized Jews an attractive religious option, which many of them took.
Hellenic culture was less conservative then the Roman tradition. There was remarkable compatibility between Christian doctrine and Greek philosophy.
Almost two-thirds of the Hellenic cities had a church by the end of the first century, and no Hellenic city lacked a church by 180. In contrast, two-thirds of less Hellenic cities still had no church in 180.
4. Larger cities had Christian congregations sooner than smaller cities.
The more urban a place, the higher the rates of unconventionality. The larger the population, the easier it is to assemble the “critical mass” to form a “deviant” subculture.
Three quarters of larger cities had a church by the year 100, while only a third of smaller cities did so.
Stark applied “regression analysis” to the figures and found that both Hellenism and city-size had significant, independent effects on Christianization but that the effect of Hellenism is substantially greater than that of city-size.
What can we take away from this?
Firstly, I should have spent more time studying mathematics in school.
Secondly, context matters when it comes to the spread of church planting movements.
Thirdly, Tim Keller is right—cities are critical. Reach the cities and you'll reach the world.
Fourthly, culture matters.
Fifthly, external contextual factors are not everything. Christianity faced the same contextual factors, yet it triumphed over paganism and other rivals because it differed qualitatively from them.
Lastly, God is the sovereign Lord of history. ?