Cyprian

“They are blind guides,' He says, 'of the blind. But if a blind man guide a blind man, both shall fall into a pit.' 4 Such a one is to be turned away from, and whoever has separated himself from the Church is to be shunned. Such a man is perverted and sins and is condemned by his very self. Does he seem to himself to be with Christ, who acts contrary to the priests of Christ, who separates himself from association with His clergy and His people? That man bears arms against the Church; he fights against God's plan. An enemy of the altar, a rebel against the sacrifice of Christ, for the faith faithless, for religion sacrilegious, a disobedient servant, an impious son, a hostile brother, despising the bishops and abandoning the priests of God, he dares to set up another altar, to compose another prayer with unauthorized words, to profane the truth of the Lord's offering by false sacrifices, and not to know that he who struggles against God's plan on account of his rash daring is punished by divine censure.”
― Cyprian