It certainly did add instability. The Roman Empire depended on god worship (Caeser's power as a religious leader in particular), depended on slavery, and was ve

It certainly did add instability. The Roman Empire depended on god worship (Caeser's power as a religious leader in particular), depended on slavery, and was very ethnocentric - all anathema to early Christianity. Gibbon, on the other hand, had a thesis and let the thesis shape the facts, rather than the other way around. Mike Duncan's Roman history podcast is still an awesome way to see all of the forces involved.