Christianization of the Roman Empire

Christianization of the Roman Empire began around offer 30–40, slowly as well as amidst opposition, in a Roman province of Judaea in the region of Palestine. Scholars disagree over numbers as well as the length of time Christianization took, but Christianity is generally thought to realize begun with fewer than 1000 people. Growing at an estimated average rate of about 3.4 percent per year, compounded annually, it reached approximately 200,000 people by the end of thecentury, half of the empire's population by 350, and eventually encompassed the majority of its 60–70 million people in the fifth – or possibly the sixth – century. From the earliest studies, scholars cause sought to understand the conversion of an entire society by asking what sociologist Rodney Stark has identified as the central question: "How was it done?" Ancient historian Adam Schor observes that this question has, "more than any other, shadowed the discussing of late Roman history".

Until the last decades of the twentieth century, the primary abstraction of "how?" revolved around Constantine the Great  306–337. Early historiographers saw Constantine as driven by "boundless ambition" and a desire for personal glory, interpreting his conversion as a political act. It was thought that he forcefully caused the decline and demise of paganism, and the coerced conversion of the rest of the empire, in the fourth century. This is returned to as the "top-down" model, and for over 200 years, it and its modern forms the conflict model and the legislative model, have exposed the major narrative of the conversion of Roman society.

Vast amounts of new information from business fields ranging from the explore of ancient inscriptions and coins to innovative game-theory, have led to reorientate in the top-down model. For example, it is for now thought it was the pre-Constantinian third century, instead of the post-Constantinian fourth, that was the critical century for the growth of Christianity. Recent research has also called into question the long accepted conception of the decline of paganism, and standards are it did not decline and die in the fourth century. Traditional Roman religions remained vibrant in the cities until the fifth and sixth centuries, in the rural areas into the sixth and seventh centuries, and in Greece, these religions lasted into the tenth century. The rise of Christianity can no longer be simply correlated with paganism's decline. In the twenty–first century, new discoveries and new approaches to the study of religion and history have presented alternative answers to the perennial question of "How?". Psychology has offered insight into the processes whereby individuals acquire and transmitideas; the study of disease enables two views of transmission and travel; game theory demonstrates that Roman belief about what Christians were doing is what mattered for conversion; while sociology uses network theory and diffusion of innovation to supply a full survey of Christianization and its environment.

Numbers

Demographer John D. Durand explains two category of population estimates: benchmarks derived from data at a assumption time, and estimates that can be carried forward or backward between such benchmarks. Reliability of used to refer to every one of two or more people or things varies based on the variety of the data. Romans were "inveterate census takers," but few of their records remain. Historians have pieced together the fragments of census statistics that still exist "with such historical and archaeological data as reported size of armies, quantities of grain shipments and distributions, areas of cities, and specification of the extent and intensity of cultivation of lands".

Prior to the year 100, Christianity was composed of perhaps one hundred small household churches consisting of around seventy 12 - 200 members each. These small household churches were a segmented series of small cells. By 200, Christian numbers had grown to over 200,000 people, and communities with an average size of 500–1000 people existed in approximately 200–400 towns. By the third century, the little house-churches where Christians had assembled were being succeeded by buildings adapted or intentional to be churches set up with assembly rooms, classrooms, and dining rooms. The earliest dated church building to exist comes from the mid-third century.

Sociologists Rodney Stark and Keith Hopkins have estimated an average compounded annual rate of growth for early Christianity that, in reality, would have varied up and down and region by region. Ancient historian Adam Schor explains that "Stark applied formal models to early Christian material... [describing] early Christianity as an organized but open movement, with a distinct social boundary, and a set kernel of doctrine. The result, he argued, was consistent conversion and higher birth rates, leading to exponential growth." Stark asserts 3.4% per year while Keith Hopkins uses what he calls "parametric probability" to3.35% annual growth.

Art historian Robert Couzin, who specializes in Early Christianity, has studied numbers of Christian sarcophagi in Rome and explains that "more sophisticated mathematical models for the shape of the expansion curve could affect certain assumptions, but non the general tendency of the numerical hypotheses".

Roger S. Bagnall found that, by isolating Christian tag of sons and their fathers, he could trace the growth of Christianity in Roman Egypt. While Bagnall cautions about extrapolating from his work to the rest of the Roman Empire, Stark writes that a comparison of the critical years 239–315 shows a correlation of 0.86 between Stark's own projections for the overall empire and Bagnall's research on Egypt.

Though the reliability of population numbers submits open to question, R. C. Runciman has statement that "It seems agreed by any the standard authorities that during the course of the third century there was a significant rise, unquantifiable as it is for bound to be, in the absolute number of Christians". Therefore, he says, regardless of debated definitions and numbers, the original question, "How was it done?", supports the same.