The etymological Latin root religio was understood as an individual virtue of worship in mundane contexts; never as doctrine, practice, or actual source of knowledge.[8][9] In general, religio referred to broad social obligations towards anything including family, neighbors, rulers, and even towards God.[4] Religio was most often used by the ancient Romans not in the context of a relation towards gods, but as a range of general emotions such as hesitation, caution, anxiety, fear; feelings of being bound, restricted, inhibited; which arose from heightened attention in any mundane context.[5] The term was also closely related to other terms like scrupulus which meant "very precisely" and some Roman authors related the term superstitio, which meant too much fear or anxiety or shame, to religio at times. definition of religio offered by Cicero is cultus deorum, "the proper performance of rites in veneration of the gods."[19]
Religio among the Romans was not based on "faith", but on knowledge, including and especially correct practice.[20] Religio (plural religiones) was the pious practice of Rome's traditional cults, and was a cornerstone of the mos maiorum,[21] the traditional social norms that regulated public, private, and military life. To the Romans, their success was self-evidently due to their practice of proper, respectful religio, which gave the gods what was owed them and which was rewarded with social harmony, peace and prosperity.
Religious law maintained the proprieties of divine honours, sacrifice, and ritual. Impure sacrifice and incorrect ritual were vitia (faults, hence "vice," the English derivative); excessive devotion, fearful grovelling to deities, and the improper use or seeking of divine knowledge were superstitio; neglecting the religiones owed to the traditional gods was atheism, a charge leveled during the Empire at Jews,[22] Christians, and Epicureans.[23] Any of these moral deviations could cause divine anger (ira deorum) and, therefore, harm the State