3 The Arians appeal to Dionysius as the Jews did to Abraham: but with equally little reason.
Seeing this themselves, accordingly, and having no confidence in their own position, they utter falsehoods against religious men. But it would be better for them, when isolated, and perceiving that under examination they were at a loss and put to silence on all sides, rather to have turned back from the way of error and not to claim men whom they do not know, lest being confuted by them also they should carry off all the more disgrace. But perhaps they do not wish ever to depart from this wickedness of theirs; for they emulate this characteristic of Caiaphas and his party, just as they have learned from them to deny Christ. For they too, when the Lord had done so so many works, by which He showed Himself to be the Christ the Son of the Living God, and being convicted by him, from thenceforth in all things thinking and speaking against the Scripture, and unable for a moment to face the proofs against themselves, betook themselves to the patriarch with the words, 'We have Abraham to our father', thus thinking to cloke their own unreasonableness. But neither did they gain anything by these words, nor will these men, by speaking of Dionysius, be able to escape the guilt of the others. For the Lord convicted the latter of their wicked deeds by the words, 'This did not Abraham', while the same truth again shall convict these men of their impiety and falsehood. For the Bishop Dionysius did not hold with Arius, nor was he ignorant of the truth. On the contrary, both the Jews of that day, and the new Jews of the present day inherited their mad enmity against Christ from their father the devil. Well then, a strong proof that here once more these men are saying what is not true, but are maligning the man, is the fact that neither was he condemned and expelled from the church for impiety by other bishops, as these men have been from the clergy, nor did he of his own accord leave the church as the partisan of a heresy, but died honourably within it, and his memory is retained and registered along with the fathers to the present day. For if he had held with these men, or not vindicated what he had written, without doubt he too would have been treated as these men have been.
Source: De Sententia Dionysii (New Advent)