Peter, in showing that the Church is one and that only those who are in the Church can be saved, said: "In the Ark of Noah certain persons, numbering only eight, were saved by water, which Baptism effects in like manner for you" (1 Peter 3:20). He proves and demonstrates that the solitary Ark of Noah was the figure of the One Church. If, at the time of this Baptism of the world anyone could have been saved without having been in the Ark of Noah, then he who is outside the Church could now be brought to life by Baptism.
CyprianKnowing that there is one Baptism, we who hold the head and root of the One Church know for certain that to him who is outside the Church nothing is lawful.
CyprianThe Lord withdraws when He is denied, and what is taken by the undeserving does not avail them unto salvation, since the saving grace is turned into ashes and holiness departs.
Cyprian