Stark, Rodney. "Chapter 9: Opportunity and Organization." IThe Rise of Christianity: How the Obscure, Marginal Jesus Movement Became the Dominant Religious Force in the Western World in a Few Centuries. San Francisco: Harper Collins, 1997, 191-208.
Stark finds there are two key factors which contribute to the ability of a religious movement to flourish. "The first is the degree or state regulation of religion . . . The second is the vigor of the conventional religious organization(s) against which new religions must compete" (Stark 1997, 191).
Rome was relatively free as far as religion was concerned. Though there were limitations, and though Christianity was not formally accepted, it was relatively free in most places and times (Stark 1997, 192). House churches could be easily identified. Christians took on Christian names. The movement was not secret.
Stark considers it important to analyze the view pagans took of Christians. This brings up the topic of a "religious economy," a marketplace of ideas and practices (Stark 1997, 193). This allows for analysis that is not limited to the individual convert, but which relates to the overall operation of the religious organization, comparing it with others (Stark 1997, 194). One important factor in this evaluation is the level of coercive force used by a government to manipulate religious organizations. Where there is intense repression of differing view, only small minorities will normally deviate. Where repression eases, more pluralism exists. Pluralism, in turn, makes it less likely for readically diverse groups to grow, but does allow them to try (Stark 1997, 195). Rome was very pluralistic in nature, as there was a constant influx of religions from subject territories.
Stark observes that paganism went into a steep decline in the fourth and fifth centuries. This may have occurred, at least in part, because paganism was very pluralistic and fragmented compared to Christianity (Stark 1997, 197). Stark considers whether the spread of the Isis cult could provide insight into areas where there were unmet perceived needs. In fact, Christianity spread in the same places where the Isis cult spread (Stark 1997, 199). In a related line of questioning, Stark asks what attitudes may have been held of paganism by pagans. He understands blasphemous graffiti in Pompeii to suggest that , at least in one place, people did not hold the pagan deities in high regard. He assumes this would be the case elsewhere as well (Stark 1997, 200).
There is a known tendency for society to move from polytheism to monotheism, possibly from an innate desire to have gods which show a greater scope of concern (Stark 1997, 201). Stark does note that we normally need more than one supernatural being so as to account for both good and evil without having just one deity who is too lofty to be concerned with eitehr (Stark 1997, 202).
What made Christianity more effective than paganism? Stark describes the difference between a private concern with religion and a collective concern. In a pluralistic society where religion is largely a private concern, multiple faiths can exist together, even in one person. When religion is more of a collective concern, it leads to an increased exclusivity which usually becomes dominant or goes into decline (Stark 1997, 204). The exclusivity of the Christian faith was strong enough that it became dominant ompared to the multiple private concerns of paganism. Stark illustrates this phenomenon in several different historic and cultural settings.