From “The Book of Pastoral Rule” by Pope Gregory I
There are some who investigate spiritual precepts with great care but trample upon what they analyse by the way in which they live. Hastily they showcase what they have learned, not by practice but by study. And the very words that they preach, they impugn by their habits.
Just as when a shepherd walks on steep ground, the flock follows him to the precipice, so too the Lord, through the prophet, laments the contemptible knowledge of pastors, saying: “When you drank the clearest water, you troubled the rest with your feet; and my sheep were nourished with that which you trampled with your feet and they drank that which your feet troubled.”
Indeed, pastors “drink the clearest water” when, with an accurate understanding, they imbibe the streams of truth. But the same “disturb the water with their feet” when they corrupt the study of holy meditation with an evil life. Obviously, the sheep drink that which was muddied by feet when, as subjects, they do not attend to the words that they hear but imitate only the depraved examples that they observe. While the laity thirst for what is said, they are perverted by the pastor’s works as if they were to drink mud from a polluted fountain.
Consequently, it is written: “Bad prophets are a snare of ruin.”
Likewise, the Lord speaks again of evil priests through the prophet: “They were a stumbling block of iniquity to the house of Israel.”
No one does more harm in the Church than he who has the title or rank of holiness and acts perversely. This is because no layperson presumes to refute the delinquent. Moreover, because such a sinner is honoured by the dignity of his rank, his offences spread considerably by way of example.
And yet everyone who is unworthy would flee from such a great burden of guilt if, with the attentive ear of the heart, he pondered the saying of the Truth: “He that scandalises one of these little ones who believe in me, it would be better for him that a millstone was hung around his neck and that he was cast into the depth of the sea.”
Indeed, the “millstone” symbolises the circuitousness and labour of the secular life, and the “depth of the sea" suggests ﬁnal damnation. Whoever, therefore, gives off the appearance of sanctity but destroys another by his words or example, it would be better for him that his earthly acts, demonstrated by worldly habits, would bind him to death than for his sacred office to be a source for the imitation of vice in another. Indeed, his punishment in hell would be less terrible if he fell alone.