Episode Summary
Executive Summary: Michael Shermer interviews Bart Ehrman about The Triumph of Christianity, focusing on how a tiny Jewish Jesus movement grew into a dominant empire-wide religion through gradual conversion, fertility, word-of-mouth, exclusivity, and changing Roman conditions—not a single miracle of history. The conversation also covers Ehrman’s own shift from evangelical belief to agnosticism, the historical Jesus, resurrection theology, Constantine, persecution, and the later development of afterlife beliefs.
Main Topics: Bart Ehrman’s intellectual and religious journey (Priority: 5/5): Ehrman describes moving from evangelical Christianity to liberal Christianity and eventually to agnosticism/atheism through biblical scholarship and the problem of evil. How Christianity grew from a tiny sect to a dominant religion (Priority: 5/5): The discussion explains that Christianity’s rise can be understood via ordinary social growth dynamics, not sudden mass conversions or direct divine intervention. The religious landscape of the Roman Empire (Priority: 4/5): Ehrman outlines pagan religion, polytheism, henotheism, and the appeal of a single powerful god within that cultural setting. The resurrection, salvation, and early Christology (Priority: 5/5): The conversation traces how belief in Jesus’ resurrection led followers to reinterpret his death as salvific and eventually to view him as divine. Persecution, Constantine, and imperial change (Priority: 4/5): They examine the sporadic nature of early persecution, Constantine’s conversion, and how legalization—not immediate state religion—helped Christianity expand. Afterlife, hell, and the problem of suffering (Priority: 4/5): Ehrman discusses how Christian afterlife doctrines developed as answers to suffering, justice, and human mortality, and previews his next book on the invention of the afterlife.
Key Arguments: Ehrman’s biblical scholarship undermined fundamentalist inerrancy claims by exposing contradictions, discrepancies, and historical/geographical errors in the Bible. His loss of faith was driven less by textual criticism than by the problem of evil: the existence of suffering seems incompatible with an all-powerful, benevolent God. The historical existence of Jesus is overwhelmingly likely because multiple independent sources attest to him, including Paul’s knowledge of James and Peter. Historically responsible claims must rest on shared assumptions; resurrection can be a theological claim but not a historical conclusion accepted by all historians. Christianity grew steadily through repeated small conversions and family transmission, not necessarily through dramatic mass revivals. The Roman world was fertile ground for miracle claims because ancient people already assumed divine powers acted in everyday life. Christian exclusivity—worshipping one god and refusing all others—helped differentiate Christianity from broader henotheistic or polytheistic practice. Belief that Jesus was raised from the dead led followers to reinterpret his shameful death as a sacrificial act that explained salvation. Constantine was likely drawn to Christianity because he came to believe the Christian god was more powerful than rival gods, especially in the context of war. Early persecution was real but sporadic; Christianity was not universally illegal until Diocletian’s empire-wide crackdown, and legal tolerance came only with Constantine’s Edict of Milan. Afterlife teachings became attractive because Christianity created and then solved a need that many pagans did not previously feel: judgment, resurrection, heaven, and hell. Modern Christian afterlife concepts differ from earlier Jewish and pagan ideas and developed over time, not as a single original doctrine.
Data Points: Estimated Christians at Jesus’ death: about 20 - Starting point for Christian growth around 30 CE Christians by 60 CE: 1,000 to 1,500 - Early growth estimate Christians by 100 CE: 7,000 to 10,000 - Growth by the end of the first century Christians by 150 CE: 30,000 to 40,000 - Mid-second-century estimate Christians by 400 CE: 25 to 35 million - Christian population in the Roman Empire by the fourth century Estimated Roman Empire population: about 60 million - Used to explain how Christians became roughly half the empire Approximate annual growth rate: 3% to 4% per year - Ehrman’s estimate of steady Christian expansion Alternative growth rate cited by Stark: 40% per decade - Used to compare Christianity’s growth to Mormon growth patterns Marcus Aurelius epidemic mortality: one-fourth to one-third of the empire - Second-century epidemic discussed as a possible factor in Christian expansion Edict of Milan: 313 CE - Constantine and co-emperor legalize religious tolerance State religion under Theodosius I: late 4th century - Christianity becomes official state religion only later, not under Constantine Jewish population share in the empire: 5% to 7% - Shows the Roman Empire was overwhelmingly non-Jewish and religiously diverse
Pivotal Quotes: "If you think that Jesus existed, oh man, yeah, you're bad news." — Bart Ehrman: Discussing backlash from some atheist critics after arguing that Jesus probably existed "Christianity had to slow its growth at this point." — Bart Ehrman: Explaining why conversion rates could not continue rising exponentially once the empire became saturated "What the Christians need to do is to convince a few people every now and then that the Christian God is more powerful than whatever gods they're being worshiped." — Bart Ehrman: Summarizing the mechanism of Christian expansion in the ancient world
Implications: The conversation reframes Christianity’s rise as a historical, social, and demographic process rather than a simple miracle story. It suggests that religion spreads through networks, incentives, and meaning-making, and that modern debates about faith, suffering, and afterlife remain deeply shaped by ancient developments.