Now, I'm sure we've all heard this theory at one point or another that the conversion from paganism to Christianity is what did the empire in. I believe the theory stems from much later European historians who were writing at a time when Europe's religious wars were still a recent memory, so their opinion is obviously quite biased, and yet, even bias and lies often have a grain of truth to them.
So, the question stands, just how much truth is in the claim that Jesus indirectly extinguished the light of (western) Rome?
The most obvious place to start looking is the cult of the emperor, that partially deified the office and helped give it legitimacy, which was obviously undermined by Christianity. The thing is though, given how many emperors were assassinated or usurped, and how many civil wars Rome has suffered over the years, combined with the fact that it was obvious to even the simplest of peasants that at least the current emperor was but a man of flesh and blood (the first man to be deified, the original Caesar, was stabbed to death, after all), I'm not all that sure the cult of the emperor was all that effective to begin with.
The next thing that springs to mind is that the church's social organization, mostly their tithes and authority figures, slowly, and quite possibly accidentally, undermined the position of the state which had previously enjoyed a stranglehold on the market for such things. We certainly know the church took over many of these responsibilities that traditionally belonged to the state once the government was gone, but the question is, were they moving in to fill a vacuum, or did the takeover being much sooner? Unfortunately its a theory that even if 100% spot on, wouldn't leave behind much evidence.
Finally there's the theory that's probably least obvious to a modern person. Early Christianity took the "turn the other cheek" business a lot more seriously then most modern versions of the faith; its one of the reasons that the army was at least for a time, a pagan holdout even as the empire converted around it. Perhaps Christianity played a role in the decline of the Roman legions through the subtle demilitarization of populace's mindset, thereby forcing the empire to rely more heavily on foederati, which while capable fighters, were of questionable loyalty, and many of which eventually turned on Rome.
So, any bright ideas, sources, or just plain speculation to sway the argument one way or another?