12 It is likewise a matter of extreme importance, Venerable Brethren, that you should warn and guard your flocks against the dangers arising from the contagion of Freemasonry. We have in a special Encyclical Letter shown how full of evil and danger to the State is this sect of darkness, and We have pointed out means to contract and destroy its influence. The faithful can never be sufficiently warned against this wicked faction, for although from the very beginning it conceived a deep hatred against the Catholic Church, and has ever since increased and inflamed it, its enmity is not always openly displayed, but more often exercises itself in an underhand and hypocritical way, especially among the young, who inexperienced and wanting in wisdom, are sadly ensnared by its deceits often concealed by appearances of piety and charity. As to being cautious in regard to those outside the Catholic faith, keep to what the Church prescribes, so that intercourse with them or the depravity of their doctrines may not become a source of danger to a Christian people. We know and regret, as you do, that Our power to ward off such dangers does not equal Our zeal and Our desire to do so; nevertheless We do not think it useless to excite your pastoral solicitude and to stimulate at the same time the activity of Catholics, so that our united efforts may turn aside, or a least lessen obstacles set in the way of Our common desires. And We exhort you in the words of Our predecessor Leo the Great: "Be full of pious zeal for religion, and let the anxiety of all the faithful be aroused against the most cruel enemies of souls." ( Serm . xv. c. 6). Therefore throwing off their torpid neglect let all good persons embrace the cause of religion and of the Church as their own, and let them fight faithfully and constantly on her behalf. Too often the wicked are confirmed in their wickedness and their power for evil, and win the day by the sluggishness and timidity of good persons. The efforts and zeal of Catholics have not indeed always the effect intended and to be expected; but at heart they serve to restrain the enemy and at the same time to encourage the feeble and timid, even without counting the advantages gained from the satisfaction of having fulfilled a duty. Moreover, We are not ready to admit that the zeal and activity of Catholics cannot attain their end if properly guided and with perseverance. For it ever has chanced and will happen that enterprises most surrounded with difficulties end happily, provided, as We have said they are carried out with courageous energy, guided and aided by Christian prudence. And indeed truth, naturally desired by all men, will sooner or later win men's minds. Truth may be tried and oppressed by intellectual troubles and diseases, but it can never be destroyed. All that has gone before seems to apply in a special way to Bavaria. For by God's grace, since it ranks among Catholic kingdoms, it must keep and nourish rather than accept that Divine faith which it received from its forefather. Moreover, they who in the people's name make laws to govern the kingdom are mostly Catholics, as are also many of its citizens and inhabitants, and therefore We doubt not they will aid with their utmost strength the Church, their mother, in her many trials. If all unite their efforts as energetically and actively as they ought, there will, by God's grace, be reason to rejoice at the happy results of their zeal. We recommend to all such union, for as there is nothing so baneful as discord, there is concord of spirit, when in united force they are brought to bear for some common purpose. Effectively the laws give Catholics an easy way of seeking to amend the condition and order of the State and to desire and will a constitution which, if not favourable and well-intentioned towards the Church, shall at least, as justice requires, be not harshly hostile. It would be unjust to accuse or blame any one amongst us who has recourse to such means, for those means, used by the enemies of Catholicity to obtain and to extort, as it were, from rulers laws inimical to civil and religious freedom, may surely be used by Catholics in an honourable manner for the interests of religion and in defence of the property, privileges, and right divinely granted to the Catholic Church, and that ought to be respected with all honour by rulers and subjects alike.
Source: Officio Sanctissimo (Vatican.va)