A Comm for Historymemes

Another fascinating facet is that the Romans took a certain aspect of Greek theology and ran with it full speed. Under the Interpretatio Graeca, all gods were actually the same gods - more or less. The Greek god of war was the German god of war - just worshipped under different names, seen in different clothes, with some different stories passed down. They were still, ultimately, the same god; and thus, all the world shared in a common faith.

The Interpretatio Romana is the exact same thing, just as applied to Roman religion instead of Greek religion. As the Romans came into contact with Greek culture, and shamelessly stole the bits they liked, they applied this theology to the world they conquered. Everyone's gods are everyone's gods.

While occasionally the Romans would import a foreign cult, even then they often equated that foreign cult with an established god in addition (something which later Graeco-Roman Platonism would use to espouse the view that all gods are emanations of the same, singular divinity). You get a lot of Roman religious epithets from this - the Romans liked addressing their gods with specific relevant titles or sub-names, like Mars Silvanus, Mars of the Woods, or Mars Ultor, Mars the Avenger, when calling upon gods. This becomes relevant in Interpretatio - Romans and provincials would worship the same god under the same name, by using these dual-names - such as Mars Lenus - 'Mars who is also Lenus (a Celtic god of war)'.

Goes a long way towards defusing concerns that the foreign conquerors are godless heathens - or that the conquered provincials are dirty superstitious savages. Whatever the mutual recriminations leveled between each other, they could at least be assured that the outsiders weren't risking the wrath of the gods with their strange, foreign ways - after all, they're paying respect to our gods!