If St.John knew or suspected that Cerinthus had a cutaneous disease, there would have been some sense in the refusal, or rather, as I correct myself, some probability of truth in this gossip of Irenaeus.
Ib.p.

128.
They corrupted the faith of Christ, and in effect subverted the Gospel.

That was enough to render them detestable in the eyes of all men who sincerely loved and valued sound faith.
O, no, no, not 'them!' 'Error quidem, non tamen homo errans, abominandus': or, to pun a little, 'abhominandus'.

Be bold in denouncing the heresy, but slow and timorous in denouncing the erring brother as a heretic.

The unmistakable passions of a factionary and a schismatic, the ostentatious display, the ambition and dishonest arts of a sect-founder, must be superinduced on the false doctrine, before the heresy makes the man a heretic.
Ib.p.