| Year AD | 30 | 100 | 200 | 300 | 400 |
| Est. # of Christians | 30 | 5,000 | 25,000 | 10,000,000 | 60,000,000 |
The number of Christians in the Roman Empire grew slowly during the first three centuries AD but exploded in the fourth. How was it possible that a breakaway sect of Judaism could replace paganism as the dominant religion of a sweeping, multiethnic empire? Many elements of Christianity were conducive to growth – missionaries, martyrs, convincing theology, a new ethical doctrine, and strong communities. It also mixed well with and incorporated many tenets of Platonism, which had seen widespread acceptance during the 2nd and 3rd centuries; both were philosophies that dealt beyond mere physical existence and sought to understand an immaterial soul and an immaterial God. Christianity withstood periods of persecution and was the religion of tens of millions at the end of the fourth century.
Christianity’s strong missionary impetus contributed to its growth. In the Gospel of Matthew, Jesus commanded his small group of followers to “go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit…”[1] This commission set Chrisitanity apart from contemporary religions. The Jews were not commanded to spread their religion in the same way that Christians were. They were an ethnoi – a people group, and they were not actively trying to convert people to their religion. Polytheists, too, did not have a call to proselytize. The only other religious groups with the same missionary tendencies were mystery cults.
In addition to its tendency to multiply, Christianity had charismatic leaders. The religion gained strength and credibility through martyrdom, a powerful picture of surrender and suffering for Christ’s safe. Paradoxically, the spectacle of did not put an end to Christians’ witness but strengthened it.
Christianity also possessed a rich systematic theology. Christians drew from the Platonic tradition to systematize their theology and integrated many of Plato’s beliefs. Christianity spread side by side with Platonism in the Roman Empire. Christians did not have a high status monetarily or philosophically, but they did possess a complete, coherent philosophy that explained the nature of the cosmos and humankind and withstood scrutiny. Christian theology provided compelling answers to questions about evil, salvation, and eternal life.
Christianity established a new ethical doctrine centered around agape. The Christian conception of love was different from the Roman eros or even philia, friendship. In Latin, agape is translated as caritas, which is where the English word for “charity” originates. This type of love, which transcended social status and gender, created tightly knit communities. Christians also set up charitable systems that would spread through Roman societies into the Middle Ages.
“By this everyone will know that you are my disciples, if you have love (agape) for one another.”
John 13:35[2]
Christians formed distinctive communities not based on ethnicity. In a sense, they formed a new ethnicity – a new nation. In a society organized and understood by bloodlines, the opportunity to become part of a new bloodline, the bloodline of Christ himself, appealed to many.
The Roman Empire was at the height of its power during the second century, but even during this prosperous time the fabric of the empire was beginning to fray. In 165 AD, the Antonine Plague raged through the empire. Five million people who contracted the disease died within two years of the plague’s arrival. The Romans believed that the plague was sent by an angry god – specifically, Apollo. They felt that Apollo had been angered by someone who had failed to worship him. Therefore, they blamed Christians for the god’s wrath and launched a persecution against them.
The outbreak of another plague during the turbulent 3rd century also led to the persecution of Christians. The first half of the century saw the turnover of dozens of emperors in a short amount of time until Decius took control in 250. Under Decius Christians were systematically persecuted throughout the empire, again blamed for its problems, including another massive plague in 251. Decius commanded that every inhabitant of the empire receive a libellus in return for a sacrifice to the gods. A Christians could not make the required sacrifice in good conscience and therefore could not receive a libellus and faced arrest, torture, and death. Despite the persecution Christians responded to the plague by burying the dead, regardless of their religion in life, and calling bishops to heal the sick. After the Decian persecution had subsided, Christianity and Neoplatonism alike saw four decades of growth.
[1] Matthew 28:19 New Revised Standard Version
[2] New Revised Standard Version
