9 But in the presence of such audacious evils, it is not sufficient merely to be aware of the wiles of this vile sect: we must also war against it, using those very arms furnished by the divine faith which once prevailed against paganism. Therefore, it is your task to inflame souls by persuasion, exhortation and example; nourish in the clergy and our people a zeal for religion and salvation which is active, resolute, and intrepid. These qualities frequently distinguish Catholic peoples of other nations in similar situations. It is commonly claimed that the ancient ardor of spirit in protecting their ancestral faith has grown cold among the Italian people. Nor is this perhaps false; especially since if the dispositions of both sides be inspected, those who wage war on religion seem to show more energy than those who repel it. But for those who seek salvation there can be no middle ground between laborious struggle and destruction. Therefore, in the case of the weak and sluggish, courage must be stirred up through your efforts; in the case of the strong, it must be kept active; with all trace of dissent wiped out, under your leadership and command, the result will be that all alike, with united minds and common discipline, may undertake the battle in a spirited manner.
Source: Inimica Vis (Vatican.va)