How Many Christians Were There in the Year 100?

Rodney Stark’s famous The Rise of Christianity proposed an oft-cited model for Christian growth in the early centuries of the Church:

Rather than proposing exact numbers, Stark is simply trying to prove the point that a consistent rate of growth compounds over time, even if it begins with such a small number. Nonetheless, his starting numbers are clearly much too low. Jesus himself seemed to have more than 1,000 followers. Furthermore, based on evidence from Roman and Christian sources both, we know that Christianity spread quickly and even reached high places, with Paul speaking of members of Caesar’s household (Phil 4:22) and Herod’s family (Rom 16:11) accepting the faith.

Such a small number of Christians in the year 50 simply does not make sense. How could 1,400 Christians in year 49, spread throughout the Mediterranean world, have caused a riot so serious in Rome, at the instigation of some “Chrestus,” that the Emperor Claudius expelled Jews from the city (Suetonius, Claudius, 25)? In the year 64, there must have a sizable and noticeable enough population of Christians in Rome for them to serve as an effective scapegoat for Nero’s burning of the city (see Tacitus, Annals, 15.44). In the year 79, when Pompeii was destroyed, signs of a Christian presence had already been established.

If we look at testimony closer to the year 100, we also see additional evidence about how widespread Christianity had become, even in remote areas. Pliny the Younger wrote to the Emperor Trajan in the year 112 from Bythnia and Pontus (along the Black Sea), speaks of the Christian faith spreading like a contagion throughout the cities and countryside, even to the point of emptying the Temples (temporarily at least):

The matter seems to me worthy of your consideration, especially as there are so many people involved in the danger. Many persons of all ages, and of both sexes alike, are being brought into peril of their lives by their accusers, and the process will go on. For the contagion of this superstition has spread not only through the free cities, but into the villages and the rural districts, and yet it seems to me that it can be checked and set right. It is beyond doubt that the temples, which have been almost deserted, are beginning again to be thronged with worshippers, that the sacred rites which have for a long time been allowed to lapse are now being renewed, and that the food for the sacrificial victims is once more finding a sale, whereas, up to recently, a buyer was hardly to be found. From this it is easy to infer what vast numbers of people might be reclaimed, if only they were given an opportunity of repentance.”

Around that time (or perhaps a little earlier), we also find Ignatius of Antioch writing to a network of churches, speaking of the organization of their communities, which seem to be of decent size based on their structure, with priests and deacons under the headship of the bishop. Ignatius can rely on support and communication within this group of communities, and even has to dissuade the community of Rome from ransoming him. Once again, it’s unlikely that these vibrant communities, when stacked against every other Christian community throughout the Roman and Persian Empires, would amount to less than 10,000 people.

Alan Hirsch might be closer in his estimation of at least 25,000 in his book The Forgotten Ways (4). I still think that might be low, but we’ll never be able to get an exact number, of course. We can discern, however, a clear impression of a small community that grew quickly and caught people’s attention, building momentum for even greater growth in the coming centuries. In addition to the tradition that St. Thomas brought the Gospel to India, there is even some new possible evidence that Christians were already in China by the year 100 (although this claim will need further verification).

Why does this matter? The apostles really did respond to Jesus’s command to preach the Gospel to the nations and people responded to this message eagerly from the beginning. We can become discouraged as we continue to experience a decline. Looking to the growth of the early Church should inspire us that even small numbers can make a large impact and that if we offer the world the hope that it needs, people will respond. Stark traced the first Rise of Christianity. It’s now time to start tracking another.