To Adelphius, Bishop and Confessor: against the Arians.
We have read what your piety has written to us, and genuinely approve your piety toward Christ. And above all we glorify God, Who has given you such grace as not only to have right opinions, but also, so far as that is possible, not to be ignorant of the devices of the devil. But we marvel at the perversity of the heretics, seeing that they have fallen into such a pit of impiety that they no longer retain even their senses, but have their understanding corrupted on all sides. But this attempt is a plot of the devil, and an imitation of the disobedient Jews. For as the latter, when refuted on all sides, kept devising excuses to their own hurt, if only they could deny the Lord and bring upon themselves what was prophesied against them, in like manner these men, seeing themselves proscribed on all hands, and perceiving that their heresy has become abominable to all, prove themselves 'inventors of evil things,' in order that, not ceasing their fightings against the truth, they may remain consistent and genuine adversaries of Christ. For whence has this new mischief of theirs sprung forth? How have they even ventured to utter this new blasphemy against the Saviour? But the impious man, it seems, is a worthless object, and truly 'reprobate concerning the Faith.' For formerly, while denying the Godhead of the only-begotten Son of God, they pretended at any rate to acknowledge His coming in the Flesh. But now, gradually going from bad to worse, they have fallen from this opinion of theirs, and become Godless on all hands, so as neither to acknowledge Him as God, nor to believe that He has become man. For if they believed this they would not have uttered such things as your piety has reported against them.
Source: Letters (New Advent)