IV. The Manichæan heresy corrupts the Scriptures in order to disprove the truth
This peerless Faith, dearly-beloved, this Truth proclaimed throughout all ages, is opposed by the devilish blasphemies of the Manichæans: who to murder the souls of the deceived have woven a deadly tissue of wicked doctrine out of impious and forged lies, and over the ruins of their mad opinions men have fallen headlong to such depths as to imagine a Christ with a fictitious body, who presented nothing solid, nothing real to the eyes and touch of men, but displayed an empty shape of fancy-flesh.
For they wish it to be thought unworthy of belief that God the Son of God placed Himself within a woman's body and subjected His majesty to such a degradation as to be joined to our fleshly nature and be born in the true body of human substance although this is entirely the outcome of His power, not of His ill-treatment, and it is His glorious condescension, not His being polluted that should be believed in. For if yonder visible light is not marred by any of the uncleannesses with which it is encompassed, and the brightness of the sun's rays, which is doubtless a material creature, is not contaminated by any of the dirty or muddy places to which it penetrates, is there anything whatever its quality which could pollute the essence of that eternal and immaterial Light?
Seeing that by allying Himself to that creature which He had made after His own image He furnished it with purification and received no stain, and healed the wounds of its weakness without suffering loss of power. And because this great and unspeakable mystery of divine Godliness was announced by all the testimonies of the Holy Scriptures, those opponents of the Truth of which we speak have rejected the law that was given through Moses and the divinely inspired utterances of the prophets, and have tampered with the very pages of the gospels and apostles, by removing or inserting certain things: forging for themselves under the Apostles' names and under the words of the Saviour Himself many volumes of falsehood, whereby to fortify their lying errors and instil deadly poison into the minds of those to be deceived.
For they saw that everything contradicted and made against them and that not only by the New but also by the Old Testament their blasphemous and treacherous folly was confuted. And yet persisting in their mad lies they cease not to disturb the Church of God with their deceits, persuading those miserable creatures whom they can ensnare to deny that man's nature was truly taken by the Lord Jesus Christ; to deny that He was truly crucified for the world's salvation: to deny that from His side wounded by the spear flowed the blood of Redemption and the water of baptism: to deny that He was buried and raised again the third day: to deny that in sight of the disciples He was lifted above all the heights of the skies to take His seat on the right hand of the Father; and in order that when all the truth of the Apostles' Creed was destroyed, there may be nothing to frighten the wicked or inspire the saints with hope, to deny that the living and the dead must be judged by Christ; so that those whom they have robbed of the power of these great mysteries may learn to worship Christ in the sun and moon, and under the name of the Holy Spirit to adore Manichæus himself, the inventor of all these blasphemies.
Source: Sermons (New Advent)