>>90194516a) Roman religion was literally a slave cult that deified the emperor as a god. Christianity is a religion for kings and slaves alike.
b) Rome was literally in the process of collapsing when Christendom had become the religion of the empire, and had been fully collapsed for a while by the time it had become widely embraced throughout western Europe. Christianity then formed the spiritual core that allowed the Dark Age/feudal states to rebuild - the macroscopic throughline of our *current* greatness.
So much good our inherent qualities did us, if the greatness they alone provided us didn't last.
c) Western man's greatness under pagan Rome is dwarfed by our greatness under Christ. Rome collapsed when it was on the technological precipice of an industrial revolution - Christianity saw us get back to and through an industrial revolution, and then persisted for the better part of two centuries after.
Better, AND longer lasting, than pagan "greatness"... and what do you know, it's only now that so many Christians have been lapsing that things have started to really fall apart. Funny how that works.
d) Citing the oogaboogs' failures as evidence that Christianity is not our source of greatness is like saying that eggs/steak/whey protein powder/exercise etc. isn't how the bodybuilder got his muscles, because the three year old had a tantrum and threw his plate on the floor.
If you're arguing that the innate characteristic which allowed us to acheive greatness, was our intellectual and spiritual capacity to actually understand and accept the gospel, study theology and cosmology, appreciate beauty, and therefore to be genuine devout Christians capable of maintaining and expanding the Church, and not a bunch of savage spear-chucking cannibals who aren't capable of having faith because they literally lack the intellect to know what "faith" means, and try to interpret religion in terms of what new potions and magical charms they can make... well, then sure, I'd agree with that.
tl;dr, your "proofs"... kinda suck, anon.