I found a neat youtube documentary on how Christianity was invented in Rome. From what I gather it stemmed from a Roman aristocratic family named like Flaavius and it was something to help control lower class people in a hugely growing Rome.
Been there, done that (saw video too). Have you read Freke & Gandy? I find actual ancient people as they really were, not as we mythologize them, to be fascinating. But I find continuity with the past, not discontinuity.