But a certain Samaritan being on his journey, came near him, and seeing him, was moved with compassion, and going up to him, bound up his wounds, pouring in oil and wine; and setting him upon his own beast, brought him to an inn, and took care of him. (Luke x; from the Gospel for the Twelfth Sunday after Pentecost)
...every loyal son of that Church, like the good Samaritan, pours oil and wine into the wounds of the sons of Adam, to free the guilty from sin, to strengthen the weak and feeble, to mould the lives of the virtuous nearer to the ideal of holiness. Even granting that some minister of Christ may at times fail in his duty, does it therefore follow that the power was rendered helpless and void of efficacy? Let us listen to the words of the Bishop of Hippo:"I assert [he writes] and we all assert, that the ministers of so great a Judge should be just men. Let the ministers be just, if they will. If, however, they who sit on the chair of Moses refuse to be just I find my warrant of security in my Master, of whom His Spirit said: "He it is who baptizes." [In Johannis Evang., tract. 5, n. 15]
Would that the words of Augustine had been accepted formerly and were accepted today by all those who, like the Donatists, allege the fall of a priest as a reason for rending the seamless garment of Christ and for unhappily abandoning the way of salvation!
We see how our Saint, for all his exalted genius, humbly submitted his judgment to the authority of the Church teaching. He knew that, as long as he did so, he would not swerve a finger's breadth from Catholic doctrine. More than that, in pondering the sentence: "If you believe not, you will not understand," [Isaias vii, 9] he learned with certainty that a heaven-born light —denied to the proud— serves as a beacon to the minds of those who cling closely to the Faith and meditate the word of God in a mood of prayerful humility.
He knew, besides, that it was the duty of priests —whose lips should keep knowledge [Mal. ii, 7]— since they are bound to explain and defend aright the truths of Revelation and expound their meaning to the Faithful, to penetrate the truths of Faith to the depths —so far as is allowed by Divine permission.
Pius XI, Ad Salutem