15 As yet, in the darkness of this life, we walk by the lamp of faith: let us hold also to the lamp John, and let us confound by him the enemies of Christ; indeed, let Christ Himself confound His own enemies by His own lamp. Let us put the question which the Lord put to the Jews, let us ask and say, “The baptism of John, whence is it? From heaven, or of men?” What will they say? Mark, if they are not as enemies confounded by the lamp. What will they say? If they shall say, Of men, even their own will stone them; but if they shall say, From heaven, let us say to them, Wherefore, then, did ye not believe him?
They perhaps say, We believe him. Wherefore, then, do you say that you baptize, when John says, “This is He which baptizes”? But it behooves, they say, the ministers of so great a Judge who baptize, to be righteous. And I also say, and all say, that it behooves the ministers of so great a Judge to be righteous; let the ministers, by all means, be righteous if they will; but if they will not be righteous who sit in the seat of Moses, my Master made me safe, of whom His Spirit said, “This is He which baptizes.”
How did He make me safe? “The scribes and the Pharisees,” He says, “sit in Moses' seat: what they say, do; but what they do, that do not ye: for they say, and do not.” If the minister is righteous, I reckon him with Paul, I reckon him with Peter; with those I reckon righteous ministers: because, in truth, righteous ministers seek not their own glory; for they are ministers, they do not wish to be thought judges, they abhor that one should place his hope on them; therefore, I reckon the righteous minister with Paul.
For what does Paul say? “I have planted, Apollos watered; but God gave the increase. Neither is he that plants anything, nor he that waters; but God who gives the increase.” But he who is a proud minister is reckoned with the devil; but the gift of Christ is not contaminated, which flows through him pure, which passes through him liquid, and comes to the fertile earth. Suppose that he is stony, that he cannot from water rear fruit; even through the stony channel the water passes, the water passes to the garden beds; in the stony channel it causes nothing to grow, but nevertheless it brings much fruit to the gardens.
For the spiritual virtue of the sacrament is like the light: both by those who are to be enlightened is it received pure, and if it passes through the impure it is not stained. Let the ministers be by all means righteous, and seek not their own glory, but His glory whose ministers they are; let them not say, The baptism is mine; for it is not theirs. Let them give heed unto John. Behold, John was full of the Holy Spirit; and he had his baptism from heaven, not from men; but how long had he it? He said himself, “Prepare ye the way for the Lord.” But when the Lord was known, Himself became the way; there was no longer need for the baptism of John to prepare the way for the Lord.
Source: Tractates on the Gospel of John (New Advent)