Cyril of Alexandria: heretics are worse than pagans

Reformed Covenanter

Puritanboard Commissioner
They who have become inventors of unholy heresies, profane and apostate and enlarging their unbridled mouth against the Divine glory and uttering things perverted, will be caught as having of their folly slipped into charges not slighter than those of the infatuation of the Greeks or haply into charges even surpassing theirs. For it were better for them not to have known the way of truth than having known it to turn back from the holy commandment given to them: for the true proverb hath come to them, The dog returned to his own vomit, and, The washed sow to the wallowing in the mire.

For they parted amongst themselves the charges of blasphemy against Christ and like fierce and bitter wolves they waste the flocks for which Christ died, and despoil what is His, multiplying to themselves that which is not theirs, as it is written, and weighting their yoke heavily, of whom may be said with much reason, They went out from us but they were not of us.

For the reference, see Cyril of Alexandria: heretics are worse than pagans.