The historical significance of the victory of proto-orthodox Christianity can scarcely be overstated. The form of Christianity that emerged from the conflicts of the second and third centuries was destined to become the religion of the Roman Empire. From there it developed into the dominant religious, political, economic, social, and cultural institution of the West for centuries-down to the present. Christians living in the midst of these conflicts could not have imagined how important their outcome would be for the shape of western civilization. The repercussions are still felt today, in ways that even we may have difficulty understanding.
Throughout this study I have tried to hypothesize what it may have been like if some other side had "won." If the Marcionite Christians had gained ascendancy, would people still ask, "Do you believe in God?" Or would they ask, "Do you believe in the two Gods?" Would anyone except scholars of antiquity have heard of the Gospels of Matthew, Mark, and John? Would we have an "Old" Testament? How would the social and political relations of Jews and Christians over the centuries have been affected? Would Christians who rejected the Jewish God and all things Jewish feel a need to polemicize against and attack Jews? Or would they simply ignore Jews as not presenting any real competition to their own claims of the knowledge of the other God, who saved them from the creator? Would anti-Semitism be worse, or would it be nonexistent?
If, on the other hand, Ebionite Christians had gained ascendancy, would Christianity have remained a sect within Judaism? Would Christians today worship on Saturdays instead of Sundays? Would they keep kosher? Would these Jewish-Christians have wanted or been able to convert masses of people to their message of salvation, when conversion would have required men to undergo the operation of circumcision? Would Christianity have been anything but a footnote in the history of world religions?
We can probably say with some certainty that if some other side had won-Marcionite, Ebionite, some form of Gnostic-there would have been no doctrine of Christ as both fully divine and human. As a consequence, there would have been no doctrine of the Trinity. How would that have affected the intellectual life of the Middle Ages, the development of scholastic modes of argumentation, the modern Christian debates over the relationship between divine revelation (say, of religious mystery) and human reason (which cannot comprehend the depths of mystery)?
These questions affect everyone, not merely those who call themselves Christian. The beliefs, practices, and institutions of Christianity have played an enormous role in western civilization as a whole, not just for members of the Church. Take the New Testament itself, for example, considered by more people throughout the course of its history to be a single book, with a unified message that serves as the ultimate basis for this religion's faith and practice. The New Testament has been and continues to be the most widely read and revered book in the history of the West. It continues to inspire belief, to stimulate reflection, and to provide hope to millions. It is preached from the pulpit; it is studied in the university; it is attacked by skeptics; it is revered by believers. In the United States it is widely considered to have been a foundation document for the founders; it is quoted on the floor of the Senate to justify acts of war and at peace rallies to oppose the use of military force; its authority cited by both opponents and proponents of the right of a woman to have abortion, by both opponents and proponents of the death penalty, by both opponents and proponents of gay rights. It was used to justify slavery and abolish slavery. It has been used to justify capitalism and socialism. It has been used for good and for evil.
But where did this book come from? It came from the victory of the proto-orthodox. What if another group had won? What if the New Testament contained not Jesus' Sermon on the Mount but the Gnostic teachings Jesus delivered to his disciples after his resurrection? What if it contained not the letter Paul and Peter but the letters of Ptolemy and Barnabas? What if it contained not the Gospels of Matthew, Mark, Luke, and John but the Gospels of Thomas, Philip, Mary, and Nicodemus? Or what if it did not exist at all?
In considering the importance of the victory of proto-orthodox Christianity, we should also reflect on broader historical implications. A case can be made that this victory was one of the most significant events in the social and political history of western civilization. Had it not happened, one could argue, the vast majority of people in the world who adhere to Christianity-some two billion by some recent estimates, the largest religion on the planet-would still be pagans, adhering to one or another polytheistic religion. The history of western civilization as we know it, from late antiquity through the Middle Ages, to the Renaissance, the Reformation, and into modernity, would never have occurred.
The grounds for this argument have to do with the conversion of the Roman Empire. Probably no ten-year period was more important for the fortunes of Christianity than 303-13 CE, well after the conflicts we have been discussing had been resolved and proto-orthodoxy had established itself as the dominant form of Christian faith. That decade near the beginning of the fourth century saw a shift in Roman imperial policy away from a massive proscription and persecution of Christians to the conversion of the Roman emperor himself and the beginnings of an enormous bestowal of imperial favors on the Christians, which ultimately led to large-scale conversions and to the declaration of Christianity as the official state religion some decades later.
The political history of the period, including church-state relations, is complicated, but for our purposes a brief sketch will suffice, starting with a word of background. Christians of all sorts had been subject to local persecution from the beginning of the religion (2 Cor. 11:23-25); but it was not until the mid-third century that there was any official, empire-wide attempt to eliminate the religion. From about 249 CE onwards, starting with the brief reign of the emperor Decius (249-51), there were periods of persecution, sporadically and inconsistently enforced, along with times of peace. For the most part, these persecutions, like the local ones in earlier periods, were occasioned not by antireligious sentiment but precisely by religious sentiment. Many pagans took their religions seriously. It was widely believed that the gods were kind and gracious, but when offended they could become angry and would need to be appeased. And nothing angered them more than the failure of people to worship them by performing the prescribed acts of sacrifice. Christians, of course, refused to sacrifice to the pagan gods, even the gods of the state. They were sometimes blamed, then, for disasters that occurred-famine, drought, disease, earthquake, political setbacks, economic difficulties-and the persecutions were designed to force them to recant and show due reverence to the gods who had long been honored by the state.
In 303 CE, the pagan emperor of the eastern part of the empire, Diocletian, ordered a persecution of Christians, matched to some degree by a persecution in the western part of the empire by his colleague, the emperor Maximian. Several imperial edicts were issued that called for the burning of Christian books, the demolition of Christian churches, the removal of class privileges for Christians, and eventually the imprisonment of high-ranking Christian clergy. In 304, a further edict required all Roman subjects to perform sacrifices to the gods; noncompliance meant death or forced labor. This "Great Persecution," as it is called, lasted on and off for nearly a decade, well beyond the retirement of Diocletian and Maximian in 305 CE. But the persecution failed to force the majority of Christians to recant. For a variety of reasons, official toleration for Christians was pronounced in both the western and eastern parts of the empire by 313. Throughout the empire people were granted freedom of religious choice, and the property of the Christians was restored.
As a result of the favors Constantine poured out upon the church, conversion to the Christian faith soon became "popular." At the beginning of the fourth century, Christians may have comprised something like 5 to 7 percent of the population; but with the conversion of Constantine the church grew in leaps and bounds. By the end of the century it appears to have been the religion of choice of fully half the empire. After Constantine, every emperor except one was Christian. Theodosius I (emperor 379-95 CE) made Christianity (specifically Roman Christianity, with the bishop of Rome having ultimate religious authority) the official religion of the state. He opposed the surviving pagan religions and eventually banned pagan sacrificial practices. More conversions naturally followed, until Christianity became the religion to be handed down to the Middle Ages and onwards.
None of this would have happened without Constantine's "conversion." And now the question of relevance to our study. If any other form of early Christianity had established itself as dominant within the religion, would Constantine have embraced it? Would he have been willing to adopt a Jewish form of Christianity, which would have required him and his fellow converts to become Jewish, undergo circumcision, keep kosher food laws, and observe other traditions of the Jewish Law? Or would he have been inclined to accept a Marcionite form of Christianity, which could claim no "ancient" roots, since it abandoned the ancient traditions of Judaism? Would he have been likely to adopt any of the Gnostic forms of Christianity, which maintained that only a spiritual elite could truly understand the revelation of God, that the majority of believers misunderstood the true teachings of Jesus?
It is difficult to see how any of these alternatives could have been attractive to the emperor or would have served to unite the empire. If one of them had become dominant, would Constantine have converted to this faith and promoted it throughout his domain? If he had not, would Christianity have become the "official" religion of the empire some decades later under the emperor Theodosius? If not, would it ever have been anything but another minor religion in an empire filled with religions? To put the question bluntly: Would Christianity have become the religion of the empire? Of the Middle Ages? Of the modern West? And if not, wouldn't those who eventually confessed Christianity-the vast majority of people around the northern and southern Mediterranean, medieval Europe, and on into the new world-wouldn't they, or rather we, have remained pagan? Wouldn't most people today still worship many gods through periodic offerings of animal sacrifice?
All things considered, it is difficult to imagine a more significant event than the victory of proto-orthodox Christianity.