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

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

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.

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).

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.

Some modern scholars contend that in terms of what "religion" was in that [Roman-era setting], you can't even call Christianity a religion.

"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.