The great pope laments the ravages suffered by the Church of God at the enmity of the ravening wolves dressed as sheep. He sets himself on the watchtower and calls the bishops to join him, ever vigilant, for the sake of the little ones whom the Devil, through his minions on earth, seeks to deceive, kill, and destroy.
Let us read the opening paragraphs of Probe nostis:
You are well aware, venerable brothers, of the many misfortunes which now afflict the Catholic Church. You know, too, that holy religion is being attacked by the pollution of errors of every kind and by the unbridled rashness of renegades. At the same time heretics and unbelievers attempt by cleverness and deceit to pervert the hearts and minds of the faithful You are aware, in shore, that practically no effort has been left untried in the attempt to overthrow the unshakeable building of the holy city. In particular, We are obliged, alas! to see the wicked enemies of truth spread everywhere unpunished. They harass religion with ridicule, the Church with insults, and Catholics with arrogance and calumny. They even enter cities and towns, establish schools of error and impiety, and publish their poisonous teachings which are adapted to secret deceit by misusing the natural sciences and recent discoveries. Furthermore they enter the hovels of the poor, traverse the countryside, and seek the acquaintance of the farmers and the lowest classes. They try every method of attracting the uneducated, especially the youth, to their sects, and of making them desert the Catholic faith, whether by means of Bibles inaccurately translated into the vernacular, pestilential newspapers and pamphlets of little weight, or by seductive speeches, pretended charity, and gifts of money.
2. We mention events which you yourselves witness. For despite your sorrow and your pastoral denunciations, you are obliged to tolerate in your dioceses these men spreading heresy and unbelief, these assertive preachers who ceaselessly waylay and ravage your flock by going around in sheep’s clothing while inwardly they are ravening wolves. What more can We add? There is hardly any uncivilized district left in the entire world to which headquarters of the main societies of heretics and unbelievers have not sent scouts and emissaries without counting the cost. These men, by waging secret or open war on the Catholic religion and its pastors and ministers, tear the faithful from the bosom of the Church and prevent unbelievers from entering it.
3. You can easily imagine the straits in which We live, since We are laden with the care of Christ’s flock and the churches, and must therefore render a detailed account to the divine Prince of Shepherds. For this reason We decided to recall in this letter the causes of the troubles which beset both Us and you. You can then reflect how important it is for all the bishops to redouble their efforts so as to break the assault of the enemies, to beat back their attacks, and to forewarn and protect the faithful from their clever appeals. We have been doing this, and We shall not stop. We know that you have likewise done so, and We are confident that you will continue.