How come Italy used to be the center of the civilized world,

[Genital Doli]

the christian identity had become far more important than the identity associated with citizenship and rome (this is rly common because of gibbon theme that you see over and over again) and thus the latters fall was regarded, mostly, as a non-event. the "last" roman emperor was some kid who no one even cared about. (even tho the real last roman emperor was constantine xi in constantinople but i digress)

[Plug Drugs]

the christian identity had become far more important than the identity associated with citizenship and rome (this is rly common because of gibbon theme that you see over and over again) and thus the latters fall was regarded, mostly, as a non-event. the "last" roman emperor was some kid who no one even cared about. (even tho the real last roman emperor was constantine xi in constantinople but i digress)

the collective consciousness' sense of "identity" and ego (which 'religion' could most undoubtedly be categorized under psychologically) only comes secondary in the human mind's priority to realistic affairs such as socioeconomics (one's "role" in society) and survival.
You could say that the western empire had become lazy, or that the extent of its territories had simply become too large for it to manage and northern barbarians found this exploitable,
but does religion have something to do with it? Probably not. Religion only reinforces what's already present in the mind