The gospel of Jesus, what Jesus himself taught his followers, was quickly augmented within the Christian movement with a gospel about Jesus, a description of who Jesus was and why his life and teachings were so important. This gospel about Jesus proclaimed that he was more than merely human and more than merely one more prophet in a long line of Jewish prophets. He was the Messiah, a special and unique messenger from God, or perhaps he was even God incarnate. The Christian movement would later decisively emphasize the latter of these interpretations, but such a degree of clarity did not exist in the early decades. Everyone agreed, however, that Jesus was no mere mortal. He was the Christ (the anointed of God), and the gospel preached by his followers would ever after combine the message of Jesus of Nazareth with this additional message about Jesus the Christ.
Christianity’s Original Diversity
During the first two centuries of its existence, Christianity remained a small religious movement with no discernible center or governing structure. Groups of Christians in different locations held widely varying opinions about almost every aspect of the movement, including who Jesus was, what salvation entailed, how the movement was related to Judaism, when and how the world would end, which sources of authority should guide the movement, and how the movement should be organized. The Bible had not yet been compiled, and institutional church structures were weak or nonexistent. It was a movement led by charismatic, often self-appointed, individuals who sometimes had conflicting visions for the movement’s future. Even at the local level, Christians had their differences. In the Apostle Paul’s first letter to the Corinthians, he indicates that many Christians in that city looked to a person named Apollos as their main guide and teacher, others looked to Peter, some followed Paul himself, and a few apparently claimed direct access to Christ with no need for any human teacher. Unanimity was clearly not the norm.
A short book called the Didache (meaning “teaching”), written around the year 100, advised early Christians about how to conduct themselves in this diverse and fluid environment. One immediate concern was evaluating the many wandering Christian prophets and preachers who traveled from town to town, providing instruction and seeking support from local Christian communities. The Didache says these peripatetic prophets should initially be welcomed as fellow believers, but they should be designated as false teachers if they stayed too long (more than two nights), if they asked for money or food, or if they failed to follow their own guidance. The document’s advice on baptism is similarly practical and flexible. Instead of mandating one specific mode of baptism, the Didache says it is best to baptize individuals in a cold spring-fed stream, but if a stream is not available, then a cold lake or pool will do; if cold water cannot be found, then warm water is satisfactory; and if there is not enough water for full immersion, then pouring water over a person’s head will suffice. Early Christianity was adaptable, and Christians felt little need to endorse just a single way of doing anything.2
Multiple versions of Christianity flourished alongside each other. Some Christian groups continued to insist that followers of Jesus needed functionally to become Jews and to obey the entirety of Jewish law. Other Christians adopted a position at the opposite extreme and condemned Judaism as thoroughly mistaken and evil. A person named Marcion, who grew up on the southern coast of the Black Sea and later moved to Rome, was the most prominent champion of this antisemitic perspective; he was also the first person to publish a collection of specially selected sacred Christian texts that prefigured the New Testament. Marcion’s compilation included the Gospel of Luke, the book of Acts, and most of Paul’s letters, but he removed anything in those texts that reflected favorably on Jews. Marcion and his antisemitic proto-New Testament were eventually rejected by the church in Rome where he was a member, but a separate Marcionite church continued to exist for several centuries. Another Christian group called the New Prophecy believed that God was still speaking directly to humankind through prophets whose words were as authoritative as those of Jesus. The movement was nominally led by a man named Montanus, but its prophetic oracles were both women, Prisca and Maximilla. Another significant subgroup of early Christians were called Gnostics, who delighted in formulating complex metaphysical descriptions of the universe and all the spiritual beings, both good and evil, that inhabit it. Gnostics claimed that Jesus had provided them with secret knowledge about how to negotiate their way through a complex and spiritually crowded universe after death and eventually make their way to heaven. The perspectives of Gnostics, Marcionites, members of the New Prophecy, and many others were all part of the early Christian amalgamation, and there was no central authority to adjudicate their conflicting claims.
Emergence of the Great Church
During the late second and early third centuries, a group of Christian bishops from the major cities of the Roman Empire launched a concerted effort to bring more structure, order, and male control to the movement. The immediate goal was to establish their own authority to govern the movement, and their proposals were based on a new theory called “apostolic succession.” Apostolic succession operates along the same lines as a modern self-perpetuating board of trustees that chooses its own successors. For the early Christian movement, apostolic succession was established when Jesus selected his disciples and invested them with special authority to lead the movement in his post-ascension absence and when Christ’s apostles then chose their successors and gave them special authority to lead the church. Those leaders subsequently had chosen their successors, and so on right up to the present day.
Bishops who could trace their lineage of leadership succession back to Jesus viewed themselves as having special authority within the movement and as having a special responsibility for imposing order on a movement that many of them considered to be much too freewheeling. Slowly these bishops formed themselves into a network of orthodox (“right-believing”) Christian leaders who began establishing boundaries around their wing of the Christian movement, which they called the Great Church or simply the Church. Identifying heresy (wrong belief) became a focus of attention, and volumes with titles like Against All Heresies, written by Irenaeus who was bishop of the city of Lyon (France) from around 180 to 202, became standard texts for deciding who was in and who was outside the Great Church. Formal church membership now became a major concern, and Cyprian (208–258), the bishop of Carthage, bluntly declared that no one could “have God as Father who does not have the church as mother.”3 The bishops were never able to attract or corral everyone who called themselves followers of Jesus into the Great Church, but over time a majority of Christians became associated with their version of Christianity, and it developed into the mainstream of the movement.
There were advantages and disadvantages to Christianity’s new organization and visibility. On the plus side, better organization helped the movement grow, since a standardized faith was easier to explain to others. On the negative side, persecution of Christians increased. Before 200, Christians in the Roman Empire were only occasionally subjected to persecution, primarily because the movement was too inconsequential to attract much attention. Once Christianity became better organized and more socially visible, Christians became useful scapegoats and popular targets for abuse. Persecution was especially intense between the years 250 and the early 300s when the Roman economy weakened and social unrest increased. It is estimated that five to ten thousand Christians were put to death during these years. That number represents less than 1 percent of all the Christians who lived in the empire at the time, but the executions were highly visible events – they were part of the “entertainment” that was staged in the colosseums and circuses in every Roman city – and having the courage willingly to die for one’s faith became woven into the fabric of Christian identity.
The Roman Imperial Church
At the height of the worst persecution Christians had ever faced, a dramatic