9 By this means men are deceived, so that they either do not undertake, or rashly attempt, a better life; because, when they choose to praise, they praise without mention of the evil that is mixed with the good: and those who choose to blame, do so with so envious and perverse a mind, as to shut their eyes to the good, and exaggerate only the evils which either actually exist there, or are imagined. Thus it happens, that when any profession has been ill, that is, incautiously, praised, if it has invited men by its own reputation, they who betake themselves there discover some such as they did not believe to be there; and offended by the wicked recoil from the good.
Brethren, apply this teaching to your life, and hear in such a manner that you may live. The Church of God, to speak generally, is magnified: Christians, and Christians alone, are called great, the Catholic (Church) is magnified; all love each other; each and all do all they can for one another; they give themselves up to prayers, fastings, hymns; throughout the whole world, with peaceful unanimity God is praised. Some one perhaps hears this, who is ignorant that nothing is said of the wicked who are mingled with them; he comes, invited by these praises, finds bad men mixed with them, who were not mentioned to him before he came; he is offended by false Christians, he flies from true Christians.
Again, men who hate and slander them, precipitately blame them: asking, what sort of men are Christians? Who are Christians? Covetous men, usurers. Are not the very persons who fill the Churches on holidays the same who during the games and other spectacles fill the theatres and amphitheatres? They are drunken, gluttonous, envious, slanderers of each other. There are such, but not such only. And this slanderer in his blindness says nothing of the good: and that praiser in his want of caution is silent about the bad....Thus also in that common life of brethren, which exists in a monastery: great and holy men live therein, with daily hymns, prayers, praises of God; their occupation is reading; they labour with their own hands, and by this means support themselves; they seek nothing covetously; whatever is brought in for them by pious brethren, they use with contentedness and charity; no one claims as his own what another has not; all love, all forbear one another mutually.
You have praised them; you have praised; he who knows not what is going on within, who knows not how, when the wind enters, ships even in harbour dash against one another, enters as if in hope of security, expecting to find no man to forbear; he finds there evil brethren, who could not have been found evil, if they had not been admitted (and they must be at first tolerated, lest they should perchance reform; nor can they easily be excluded, unless they have first been endured): and becomes himself impatient beyond endurance.
Who asked me here? I thought that love was here. And irritated by the perversity of some few men, since he has not persevered in fulfilling his vow, he becomes a deserter of so holy a design, and guilty of a vow he has never discharged. And then, when he has gone forth himself too, he also becomes a reproacher, and a slanderer; and records those things only (sometimes real), which he asserts that he could not have endured. But the real troubles of the wicked ought to be endured for the society of the good.
The Scripture says unto him: “Woe unto those that have lost patience.” And what is more, he belches abroad the evil savour of his indignation, as a means to deter them who are about to enter; because, when he had entered himself, he could not persevere. Of what sort are they? Envious, quarrelsome, men who forbear no man, covetous; saying, He did this there, and he did that there. Wicked one, why are you silent about the good! You say enough of those whom you could not endure: you say nothing of those who endured your wickedness....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)