That it must be Ascribed Equally to Christ and the Holy Ghost that his Flesh and Humanity Became the Temple of God.

The Seven Books of John Cassian — John Cassian

But there follows in your blasphemy that His flesh was made a temple of the Holy Ghost, for this reason, that John has said: "For I saw the Spirit descending from heaven and abiding upon Him." [2651] For you try to support even this wild statement of yours by Scriptural authority: wherefore let us see whether this sacred authority has said that which you say. "For I saw," it says, "the Spirit descending like a dove, and abiding upon Him." Discern here, if you can, which is the more powerful, which greater, which more to be honoured? He who descended, or He to whom the descent was made? He who brought down the honour, or He to whom the honour was brought? Where do you find in this passage that the Spirit made His flesh a temple? or wherein does it lessen the honour of God, if God Himself descended to show God to mankind? For certainly we ought not to think that He is less whose high estate was pointed out, than He who pointed out His high estate. But away with the thought of believing or making any separation in the Godhead: for one and the same Godhead and equal power shut out altogether the wicked notion of inequality. And so in this matter, where there is the Person of the Father and of the Son and of the Holy Ghost, and where it is the Son of God to whom the descent is made, the Spirit who descends, the Father who gives His witness, no one had more honour, and no one received any slight, but it all redounds equally to the fulness of the Godhead, for each Person of the Trinity contains within Himself the glory of the whole Trinity. And so nothing further needs to be said, except only to show the rise and origin of your blasphemy. For thorns and thistles springing up from the roots produce shoots of their own nature, and from their character show their origin. So then you also, a thorny offshoot of the Pelagian heresy, show in germ just the same that your father is said to have had in the root. For he [2652] (as Leporius his follower said) declared that our Lord was made the Christ by His baptism: you say that at His baptism He was made the temple of God by the Spirit. The words are not altogether identical: but the wrong-headedness is altogether the same.

Footnotes:

[2651] S. John 1:32.

[2652] Ille enim; viz., Pelagius. This appears to be the true reading, though one ms. followed by Gazæus has Leporius ille enim; a reading which would involve the supposition that there were two persons of the name of Leporius, master and scholar.