The Triumph of Christianity

by Bart D. Ehrman

  The document was not revealed to be a forgery until the middle of the fifteenth century. Before that it was taken to authorize papal control of Western Europe. The thirteenth-century pope Gregory IX (pope from 1227 to 1241) used the document to confront Frederick II, king of Sicily, arguing that “Constantine had given to the bishop of Rome the imperial insignia and scepter, the city with its entire duchy, and also the empire with perpetual oversight.” More explicitly Pope Boniface VIII (pope from 1294 to 1303) declared: “I am Caesar; I am the emperor.”3 How much more powerful could a leader of the church be? For him, the takeover of the empire was complete. This was a triumph indeed.

  But not, obviously, for everyone else. If victory for one means defeat for others, we might consider what was lost with the Christianization of the empire.

  On one level, it is impossible to say that Christianity caused the disappearance of so much that was lost. What we can say is that much that was alien to Christianity did indeed disappear. A great deal of pagan culture was eventually destroyed or, at least, never renewed. We have seen the beginnings of the destruction in the fourth century, with temples, shrines, and cult statues taken down and mutilated. Some, of course, remain, adorning many of the great museums of the world or left, in some instances, intact at archaeological sites on their places of origin. But most went away forever, destroyed by fervent bishops or marauding monks.

  Other artifacts that were not made of marble and stone disappeared out of neglect. All sorts of literature, gone forever, thousands of books known and suspected to have once existed: plays, novels, poems, histories, philosophical works, scientific treatises, essays, name your genre. It is not that these were necessarily burned by zealous Christians opposed to the classics, although that sometimes did happen. Instead, they simply were never recopied for posterity. And for a simple reason: copyists throughout the Middle Ages were almost invariably Christian monks working in monasteries. They were far more interested in producing copies of the letters of Paul than the plays of Plautus. Such pagan works may have been lost anyway, of course, without the Christianization of the empire. We can never say.

  Apart from artifacts of broader culture, there were losses sustained within the realm of religion itself. The triumph of Christianity meant a new kind of religiosity, and it is worthwhile thinking about the significance of the change. The Christianity that Theodosius and his successors promoted, sometimes with vigorous legislation and imperial force, was strictly Nicene orthodoxy. This form of Christianity was doctrinaire, insisting on certain theological views as the only right basis for all religious belief. Variation—even in seemingly minute details of theological niceties—came to be disallowed. There was one form of truth, and eternal life depended on knowing what it was.

  One thing lost in this triumph was all the massive and glorious diversity of religious expression found everywhere throughout the pagan world. We can never lose sight of just how varied the thousands of pagan cults were. They did share common features—sacrifice and prayer, for example. But they involved the worship of different gods, known from different myths, adored through different practices, cults devoted to Zeus, to Athena, to Apollo, to Hephaestus, to gods of forests and streams and meadows, to gods of the household and gods of the family. As a rule this enormous diversity brought with it a widespread tolerance of difference, a sense that varying paths to the divine were not only acceptable and allowed but also desirable. Tolerance was to be encouraged. Freedom of religion was to be embraced. One of the greatest aspects of ancient paganism, taken as a whole, was the widespread willingness to accommodate and even revel in diversity. That was lost with the triumph of Christianity.4

  But changed as well was a world that separated religion, ethics, philosophy, and myth into distinct spheres of human thought and life. Now with the triumph of Christianity there appeared on the scene a “totalizing” discourse about religion that encapsulated the totality of the lives of those who adhered to it, affecting not just their cultic practices but also the moral precepts they followed, the stories they told about the divine, and the views they embraced not just about God but about reality itself. Christianity not only took over an empire, it radically altered the lives of those living in it. It opened the door to public policies and institutions to tend to the poor, the weak, the sick, and the outcast as deserving members of society. It was a revolution that affected government practices, legislation, art, literature, music, philosophy, and—on the even more fundamental level—the very understanding of billions of people about what it means to be human. However one evaluates the merits of the case, whether the Christianization of the West was a triumph to be treasured or a defeat to be lamented, no one can deny it was the most monumental cultural transformation our world has ever seen.

  Appendix

  THE RATE OF CHRISTIAN GROWTH

  In 1996, Rodney Stark published a book for general audiences called The Rise of Christianity.1 In it he explained sociological factors that, in his judgment, led to the triumph of Christianity in the Roman world. The book was not well received by experts in the field of early Christian studies, who noted numerous flaws in Stark’s reasoning and, especially, in his uncritical use of ancient sources.2 But even though Stark is not a historian of ancient Christianity, he is a sociologist. As a sociologist, he knows how to calculate population growth. Far and away the most significant and intriguing part of his book are his calculations.

  Stark did something no one before him had tried. He actually did the math. Suppose, he says, Christianity had 1,000 adherents in the year 40 CE. How quickly would it need to grow in order to reach 10 percent of the empire—6 million people—by the year 300? Would the rate of growth need to be miraculous? Or would there need to be massive conversions for three centuries? No, on both scores. There would need to be a steady rate of growth. And an absolutely plausible one. To get from 1,000 Christians to 6 million 260 years later, the church would need to grow at a rate of about 40 percent per decade.

  That’s actually not that much. It is 3.4 percent per year. If this year there are 100 Christians, next year there need to be 103 or 104. In other words, in any group of 100 Christians, only 3 or 4 of them need to make a single convert each over the course of the entire year, or one of them needs to convert just one small family unit.

  A steady rate of growth involves an exponential curve. At first not many people are converting. But at the same exact rate later, when there are lots more converts, the numbers suddenly become enormous. Those 3 or 4 converts that you win when there are only 100 of you become 30,000 or 40,000 (in one year!) when you number 1 million. It is like compound interest. At one point you have trouble believing it is happening, but it is and you are making money hand over fist. It does not require substantial rates of growth. In fact, Stark revels in the fact that we have a clear historical analogy. One of his main areas of expertise is the Mormon Church. As it turns out, Mormonism had grown by 43 percent per decade from its founding to the time Stark was writing in the mid-1990s. There is nothing implausible at all about the early Christian church growing at a similar rate.

  Stark himself realized his calculations for early Christianity are very rough. In fact, as stated they do not work very well. One point Stark did not consider adequately is his opening figure: 1,000 Christians in the year 40 CE. That would be just a decade after Christianity started. For the following twenty-six decades Stark shows that the church would need to grow at a rate of 40 percent. But how do we get to the number 1,000? If the New Testament is right—and there is no reason to doubt it, since it is hard to figure out, in this particular respect, how it can be wrong—Christianity began with a small group of Jesus’s followers, men and women, something like 20 people. That would be in the year 30. If those 20 people had grown to be 1,000 by the year 40, it would be a growth rate of 4,900 percent for that decade. Are we supposed to think that for the first ten years Christianity grew at a rate of 4,900 percent but then for the next 26 decades at 40 percent? Obviously not.


  Moreover, the numbers do not work too well at the other end. Suppose Christianity grew at a relatively steady rate of 40 percent per decade for three centuries and that it comprised 6 million adherents by the year 300. What happened next? If the church continued to grow at 40 percent per decade over the next century, then by the year 400 it would have numbered 170 million. But there were only 60 million inhabitants in the empire, so that can’t be right.

  Obviously Christianity was not growing at a steady rate, and Stark, more than anyone, knows this. It is true that there must have been a rapid rate of growth early on in the movement, even if it seems unrealistic to suppose a rate of 4,900 percent per decade. But clearly, in the early years, it had to grow faster than 40 percent. That can easily be shown. If Christianity started with 20 people in 30 CE and grew at 40 percent per decade, there would have been only 55 Christians in the entire world when Paul wrote his letter to the Romans around 60 CE. But he greeted 26 people by name in just this one letter and mentioned several Christian assemblies there. This was in a church that he did not found himself—one, in fact, he had never even visited. Surely he would not have known most of the people in the church, and it was just one church. What about all the other Christians in all the other churches that we know about, in Jerusalem, Damascus, Antioch, Ephesus, Philippi, Thessalonica, Corinth, throughout the region of Galatia, and on and on? There must have been hundreds or thousands of Christians at the time, not 55. There may not have been tens of thousands, but surely there were many hundreds.

  Thus, we need to figure out how to get from 20 Christians in 30 CE to some hundreds in 60 CE. The rates of growth will be relatively high early on.

  Moreover, the rates will almost certainly need to be lower at the tail end of the period. Suppose we are right (in what I argue in chapter 6) that there might be as many as 3 million Christians in the year 300 CE but around 30 million in 400 CE. For that to happen we need a growth rate of only 25.9 percent per decade. Even if there are just 2 million at the outset of the fourth century, to get to 30 million by the end we need a growth rate of just 31.1 percent. It’s not a statistically huge difference: just under 0.5 percent more per year—that is, for a group of 100 people, one additional convert every two years.

  REVISING THE RATE OF GROWTH

  As a result of these considerations, I want to suggest some minor tweaks in the way we understand the rate of Christian growth. It is important to emphasize that there could never have been anything like a steady rate. Populations ebb and flow for all sorts of reasons. For the growth of the Christian church there are a large number of imponderables. How quickly were Christians dying in relation to the rest of the population? Did they have more births? Were persecutions occasionally cutting into their numbers? Or did the bravery of martyrs actually increase their numbers?

  Some scholars, including Stark, have tried to take such matters into consideration, but in fact probably none of them is significant. Christians were born and died at about the rate of others, despite elite Christian authors claiming that Christians never practiced abortion or infanticide. These claims have been shown to be propagandistic and cannot be accepted naïvely as factual.3 Nor, as we have seen, did improved Christian health care probably lead to better mortality rates. In addition, not enough people were actually martyred to decrease the Christian population significantly.4

  As a result, for our purposes, we will not take into account special features of Christianity that one might unreflectively suppose led to a difference. I will base my calculations on two fixed numbers. It does appear to be right that the religion started with about 20 people in the year 30, and that by the year 400 it was about half the empire—so, say, 30 million. And so the question is, how much would Christianity have to grow to get from 20 persons to 30 million in 370 years?

  Paul, as indicated, provides us with solid evidence that the initial rates of growth were sizable, especially in relation to what came later. Most of his letters are addressed to churches he had personally founded. In them he greets people by name and refers to churches in other places, but not in order to prove a point about how successful he has been or to provide statistical data for inquiring minds of the twenty-first century. He is simply writing letters to people, not realizing how these letters might be used later.

  Paul himself founded churches in the regions of Macedonia, Achaia, Asia Minor, and elsewhere. We know of his churches in Corinth, Thessalonica, Philippi, Ephesus, throughout the region of Galatia, probably in Syria and Cilicia, and possibly in the Nabataean kingdom called Arabia in the New Testament. (See, for example, Galatians 1:15–21.) He also refers to other churches he did not found: for example, in Jerusalem, Damascus, Antioch, Colossae, and Rome. Altogether sixty-five communities are mentioned in the Pauline letters (not including the Pastoral epistles of 1 and 2 Timothy and Titus). An additional thirteen are mentioned in the book of Acts.

  Moreover, there are indications that these churches each comprised more than two or three people. We have seen that Paul’s modus operandi entailed staying in a city until he had made enough converts to establish a viable community that could then begin to propagate itself. The letters themselves intimate communities that surely number in the dozens. The Christians in Thessalonica, for example, are upset that some of their number have died and Paul writes to reassure them that this will not be the fate of everyone else (1 Thessalonians 4:13–18). The clear impression is that several people within a large community have passed away.

  Or consider the church in Corinth. Paul’s first letter to the church indicates numerous problems experienced by numerous people. There are factions in the church with different members following different spiritual leaders; Paul mentions four of the factions (1 Corinthians 1:12). There are men in the church who have been visiting prostitutes and bragging about it (1 Corinthians 6). Other men have been told, in a quite different vein, that they are not supposed to have sex with anyone, even their own wives (1 Corinthians 7). There are other instances of sexual immorality (1 Corinthians 5). Some people are arguing that Christians should not eat meat from sacrifices to pagan gods and others who argue that it is perfectly acceptable (1 Corinthians 8 and 10). Some of the women are coming to church without head coverings (1 Corinthians 11). The wealthy people are coming to weekly meals and gorging themselves when others, the slaves and day laborers, have to come late and there is nothing left to eat (1 Corinthians 11). Worship services have turned chaotic as people try to show spiritual one-upmanship by speaking in unknown tongues more than anyone else (1 Corinthians 12 and 14). People are not using their various spiritual gifts for the uplifting of the community (1 Corinthians 12 and 13). Some Christians claim that they have already experienced a spiritual resurrection and have enjoyed the full benefits of salvation (1 Corinthians 15). Surely this enormous mass of problems presupposes a community of dozens and dozens of people. And this is just twenty-five years after the death of Jesus, in just one location. There could not be merely fifty-five Christians in the entire world.

  Thus it appears that the beginning of the Christian movement saw a veritable avalanche of conversions.5 Possibly many of these are the direct result of the missionary activities of Paul. But there may have been other missionaries like him who were also successful. So let’s simply pick a sensible rate of growth, and say that for the first forty years, up to the time when Paul wrote his last surviving letter, the church grew at a rate of 300 percent per decade. If the religion started with 20 people in 30 CE, that would mean there were some 1,280 by the year 60. That is not at all implausible as a guess, but it is way too precise—so let’s just say 1,000 to 1,500 Christians. But growth cannot continue at that rate. If it did, a century later, in the year 160, there would be well over 1 billion Christians in the world.

  So we can probably assume there was a burst of initial enthusiasm generated by the new faith, both among people who had heard Jesus preach during his public ministry and among those evangelized through the extraordinary missionary work of Paul and poss
ibly others like him. After Paul’s death there was almost certainly a rapid decline. The change would not be immediate or steady, but we are dealing with ballpark figures here. Say it went down on average to 60 percent per decade for the next forty years up to the end of the first century. There would still be a lot of energy and enthusiasm among those who thought not only that Jesus saved them from their sins but also that he was coming back very soon, creating a kind of urgency for their message. This would be a rate of growth just under 5 percent per year. Every year each group of 20 people needs to make just one convert. At a rate like that there would then be something like 8,389 Christians in the world in the year 100 CE. That sounds about right, but again, it is impossibly precise. So let’s just say 7,000 to 10,000.

  There is no point—and no way—to do a breakdown decade after decade. Clearly growth cannot be sustained at 60 percent, since that would give us over 100 million Christians in the year 300 when we think that there might have been 2 or 3 million. To get to 2 million there would need to be a growth rate of 31.5 percent per decade of those two hundred years; for 3 million there would need to be not much more, just 34.2 percent per decade. Just as our earlier numbers were far too precise, so too are these rates of growth, but the matter is complicated by the obvious fact that very small differences in percentage lead to unrealistic numbers of conversion. So, for broad illustration, we can simply suggest a rate of growth between 100 and 300 CE as between 30 and 35 percent per decade on average, with huge fluctuations over time, in different places, all based on external and internal circumstances.

  In the fourth century, when massive conversions occur in part because of Constantine and the favors he showered on the church, the rates of growth must have slowed down. Otherwise, again, by the end of the century there would be more Christians than inhabitants of the empire, in a time when we know for a fact there were still a large number of pagans, as both pagan and Christian authors attest. It may seem counterintuitive that we would get a slower rate of growth after the conversion of Constantine. Wasn’t that the event that changed everything? Well, not exactly. One reason the rate of growth declined (this may seem ironic) is because the numbers of converts increased. The more people who converted to become Christian, the fewer non-Christians there were to convert. And so they could not convert at the same rate simply because there were not as many of them.