WK: This is a guest post by journalist and blogger Rick Heller, who blogs at TransparentEye.This post is cross-posted here.

I was in Rome a few weeks ago, and took this photo in the entryway of the church of Santa Maria in Trastevere, one of the oldest churches in Rome. The engraving is one of a number preserved from an early date, and uses the Chi Rho symbol, which employs the first two Greek letters in “Christ.”

I’ve been reflecting on the conversion of the Greco-Roman world to Christianity, and contrasting it with the persistence of polytheism in the Hindu world (as an agnostic, I have no stake in any of these religions).

Christianity was legalized in the Roman Empire by Constantine in 313, starting a period of toleration that ended when Theodosius prohibited paganism later in the century. Paganism seems to have quickly disappeared. The pagans were apparently unwilling to die for their religion in the way that Christians were for theirs. I’m not an expert in this, but it seems to me that Greco-Roman religion, with its view of Hades, didn’t offer much in the way of an incentive for dying for one’s faith.

Hinduism, by contrast, has survived and prospered, despite the Muslim conquest of India many centuries ago (Indian Buddhism was essentially destroyed). I don’t know how to account for this, but it has been suggested to me that the Hindu belief in reincarnation gave it a strength and resilience that Greco-Roman religion lacked.

I do find engravings like the above moving. It appears to me to have been carved by a non-professional hand–certainly with less regularity than on an official Roman inscription–and thus seems like a personal communication transmitted across the centuries.