Yup everything you said about the church there is true I'd say. However, I think you might want to research Rome a little more. Riots are bred from violence, for example.

How many peaceful people begin riots?

Precisely, just as a morally declined society breeds violence.

Ex.
You care nothing about your fellow man, so what is to keep you from harming him?

A morally and ethically founded society would not struggle in this nature, because they would care for their fellow man.

But ultimately, you are on the right road I guess. In the sense of which came first the chicken or the egg.

Rome fell to multiple armies, but it was due to a lack of unity among the people, and they way they expanded themselves so abruptly and abroad. Unity is found within morality, a common bond among people. Morals can be found in just about every positive type of unification. So the lack of these morals will cause a rift among people, leading to flaw and inevitably disaster.

But please, even though you submited in thise debate, don't let that stop you from researching further.