Galen's observations reflect one of the distinctive features of early Christianity. Roman-era religion was mainly about ritual actions vis-à-vis the gods, and there was little to do with ordering behavior otherwise.

Justin Martyr says that he was impressed in his study of the Old Testament, at the seriousness and contents of these writings, and became convinced that Jesus fulfilled these texts.

I think that Rodney Stark puts his foot wrong on some things where he simply wasn't sufficiently current on scholarly developments.

Religions of the Roman world varied. Most of it was ritual practices. There were periodic occasions when cities honored their guardian deities with sacrifices and ceremonies, to ensure that they stayed happy and kept the city safe.

Studies of the people named and described in earliest Christian texts show that, right from the earliest years, they included craftsmen, merchants, and owners of businesses. Of course, there were also slaves and poor among believers. By at least the second century, there were also believers from upper levels of Roman society.

In the Marquette Lecture volume, I focus on the question in the title. I emphasize the social and political costs of being a Christian in the earliest centuries, and contend that many attempts to answer the question are banal. I don't attempt a full answer myself, but urge that scholars should take the question more seriously.

I think Rodney Stark makes a substantial contribution to the study of early Christianity in posing the kinds of questions that he pursues (which reflect his social-science background).

Justin's testimony about becoming a Christian is that he had been searching various philosophical traditions of the time, and then accidentally encountered a man who posed questions that pointed Justin [Martyr ] in a new direction.

In Destroyer of the gods I focus on several major features of early Christianity that made it distinctive, even odd or bizarre .We don't today realize just how different early Christianity was in that context.

In its Roman-era setting, for example, Christianity was so different that critics of the time referred to it as a superstition (meaning a bogus or dangerous religion).