Galen recognized, with some considerable puzzlement it seems, that Christians exhibited the virtues that he associated with the discipline of philosophy.

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.

I think that Rodney Stark studies of new religious movements in the modern world give us some insights into the kinds of questions that we can ask about early Christianity.

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

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.

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.

"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.