It is on the basis of the use of the term religio in Latin philosophers that we can understand the extension given the word in the Christian West. In Classical Latin, the meanings of religio never exactly coincided with those attested for the term “religion” in English and French, which designates both a set of practices of worship and the beliefs on which the latter are based. It was Christianity that unified the distinct uses of the word religio and defined it in relation to an object of belief, as it is expressed by the use of the objective genitive religio veri Dei ( the religion of the true God ). But if Christianity’s original contribution consisted in giving a doctrinal content to the term, it was the Roman philosophers of the first century BCE ( Cicero and Lucretius ) who changed the word’s spheres of use, and it was their polemics that established in the Latin language the oppositions that were taken up again by their Christian readers, Lactantius, Arnobius, and Augustine. (BCDU)