Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Manichæan Controversy.: Chapter 6

Chapter 6.—Why Manichæus Called Himself an Apostle of Christ.

7.  For I am at a loss to see why this epistle begins, "Manichæus, an apostle of Jesus Christ," and not Paraclete, an apostle of Jesus Christ.  Or if the Paraclete sent by Christ sent Manichæus, why do we read, "Manichæus, an apostle of Jesus Christ," instead of Manichæus, an apostle of the Paraclete?  If you say that it is Christ Himself who is the Holy Spirit, you contradict the very Scripture, where the Lord says, "And I will send you another Paraclete."  271   Again, if you justify your putting of Christ’s name, not because it is Christ Himself who is also the Paraclete, but because they are both of the same substance,—that is, not because they are one person, but one existence [non quia unus est, sed quia unum sunt],—Paul too might have used the words, Paul, an apostle of God the Father; for the Lord said, "I and the Father are one." 272   Paul nowhere uses these words; nor does any of the aposp. 132 tles write himself an apostle of the Father.  Why then this new fashion?  Does it not savor of trickery of some kind or other?  For if he thought it made no difference, why did he not for the sake of variety in some epistles call himself an apostle of Christ, and in others of the Paraclete?  But in every one that I know of, he writes, of Christ; and not once, of the Paraclete.  What do we suppose to be the reason of this, but that pride, the mother of all heretics, impelled the man to desire to seem to have been sent by the Paraclete, but to have been taken into so close a relation as to get the name of Paraclete himself?  As the man Jesus Christ was not sent by the Son of God, that is, the power and wisdom of God—by which all things were made, but, according to the Catholic faith, was taken into such a relation as to be Himself the Son of God—that is, that in Himself the wisdom of God was displayed in the healing of sinners,—so Manichæus wished it to be thought that he was so taken up by the Holy Spirit, whom Christ promised, that we are henceforth to understand that the names Manichæus and Holy Spirit alike signify the apostle of Jesus Christ,—that is, one sent by Jesus Christ, who promised to send him.  Singular audacity this! and unutterable sacrilege!

Footnotes

John xiv. 16.

John x. 30.