6 The terrible conditions existing in the times when St. Francis lived are well known to you, Venerable Brothers. It is quite true that then the faith was more deeply rooted in the people, as is proven by the holy enthusiasm with which not only professional soldiers but even citizens of every class bore arms in Palestine to free the Holy Sepulcher. However, heresies gradually arose and grew in the vineyard of the Lord, propagated either by open heretics or by sly deceivers who, because they professed a certain austerity of life and gave a false appearance of virtue and piety, easily led weak and simple souls astray. They went about, too, amid the multitudes spreading the destructive flames of rebellion. If some of these men, in their pride, believed themselves called by God to reform the Church to which they imputed the faults of private persons, even going to the length of rebelling against the teachings and authority of the Holy See, later they openly manifested the real intention by which they were inspired. It is a notorious fact that before long the greater part of these heretics ended their careers in licentiousness and vice, and succeeded in embroiling the state in difficulties and in undermining the foundations of religion, of property, of the family, and of society. In a word, what happened then is precisely what we see recurring so often in the course of the centuries; rebellions leveled against the Church are followed or accompanied by rebellions against the state, the one receiving aid and comfort from the other.
Source: Rite Expiatis (Vatican.va)