It is recorded beginning in the 1st century BC, i.e. in Classical Latin at the end of the Roman Republic, notably by Cicero, in the sense of "scrupulous or strict observance of the traditional cultus".
[citation needed] Modern scholars such as Tom Harpur and Joseph Campbell have argued that religio is derived from religare: re (again) + ligare (bind or connect), which was made prominent by Augustine of Hippo, following the interpretation of Lactantius in Divinae institutiones, IV, 28.
[7][8] Newer research shows that in the ancient and medieval world, 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.
It is sensible alike of the pleasures of love and glory, and, to a degree that is rare among men even, possesses notions of honesty, prudence, and equity; it has a religious respect also for the stars, and a veneration for the sun and the moon."[14]St.
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.
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.
Hence, a graveyard was not primarily defined as sacer but a locus religiosus, because those who lay within its boundaries were considered belonging to the di Manes.