Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 48

Chapter 48.—58.  When we ask, therefore, by what means the man is to be cleansed whom you do not baptize again in your communion, even when it has been made clear that he has been baptized by some one who, on account of some concealed iniquity, did not at the time possess the conscience of one that gives in holiness, what answer do you intend to make, except that he is cleansed by Christ or by God, although, indeed, Christ is Himself God over all, blessed for ever, 2420 or by the Holy Spirit since He too is Himself God, because this Trinity of Persons is one God?  Whence Peter, after saying to a man, "Thou hast dared to lie to the Holy Ghost," immediately went on to add what was the nature of the Holy Ghost, saying, "Thou hast not lied unto men, but unto God." 2421   Lastly, even if you were to say that he was cleansed and purified by an angel when he is unacquainted with the pollution in the conscience of him that gives but not in holiness, take notice that it is said of the saints, when they shall have risen to eternal life, that they shall then be equal to the angels of God. 2422   Any one, therefore, that is cleansed even by an angel is cleansed with greater holiness than if he were cleansed by any kind of conscience of man.  Why then are you unwilling that it should be said to you, If cleaning is wrought by the hands of a man when he is genuinely and manifestly good; but when the man is evil, but undetected in his wickedness, then since he has not the conscience of one that p. 621 gives in holiness, it is no longer he, but God, or an angel, that cleanses; therefore they who are baptized by undetected evil men are justified with greater holiness than those who are baptized by men that are genuinely and manifestly good?  And if this opinion is displeasing to you, as in reality it ought to be displeasing to every one, then take away the source from which it springs, correct the premiss to which it is indissolubly bound; for if these do not precede as hypotheses, the other will not follow as a consequence.

Footnotes

Rom. ix. 5.

Acts 5:3, 4.

Matt. xxii. 30.