Why was christianity appealing to many romans?
After the collapse of the Republic, the old Roman religion (Jupiter et. al.) was pretty much a dead faith, despite several attempts to revive it. This created a spiritual vacuum of a sort within the Empire. While there was the cult of Emperor-worship, mainly as a civic religion, the attraction of faiths came from the periphery of the Empire or even from without. Christianity was pretty much in “competition” with several other religions. Mithraism (of Persian origin) was popular among Roman legions. The cult of Isis, from Egypt, was popular as well. The advantage that Christianity had over these was that it was extremely inclusive, meaning that anyone could join. (Mithraism was limited to men, and Isis-worship place women above men.) Christianity had another thing going for it. Early Christians were willing martyrs, especially when they did not partake of the cult of Emperor-worship. (This is what Christian scripture references when it prohibits the consumption of food offered to idols.