The Epistles of Cyprian

⁴ For the faith of the sacred Scripture sets forth that the Church is not without, nor can be separated nor divided against itself, but maintains the unity of an inseparable and undivided house; since it is written of the sacrament of the passover, and of the lamb, which Lamb designated Christ: “In one house shall it be eaten: you shall not carry forth the flesh abroad out of the house.” Which also we see expressed concerning Rahab, who herself also bore a type of the Church, who received the command which said, “You shall bring your father, and your mother, and your brethren, and all your father's household unto you into your house; and whosoever shall go out of the doors of your house into the street, his blood shall be upon him.” In which mystery is declared, that they who will live, and escape from the destruction of the world, must be gathered together into one house alone, that is, into the Church; but whosoever of those thus collected together shall go out abroad, that is, if any one, although he may have obtained grace in the Church, shall depart and go out of the Church, that his blood shall be upon him; that is, that he himself must charge it upon himself that he perishes; which the Apostle Paul explains, teaching and enjoining that a heretic must be avoided, as perverse, and a sinner, and as condemned of himself. For that man will be guilty of his own ruin, who, not being cast out by the bishop, but of his own accord deserting from the Church is by heretical presumption condemned of himself.