On which place some, as if by human reasoning they were able to make void the truth of the Gospel declaration, object to us the case of catechumens; asking if any one of these, before he is baptized in the Church, should be apprehended and slain on confession of the name, whether he would lose the hope of salvation and the reward of confession, because he had not previously been born again of water? Let men of this kind, who are aiders and favorers of heretics, know therefore, first, that those catechumens hold the sound faith and truth of the Church, and advance from the divine camp to do battle with the devil, with a full and sincere acknowledgment of God the Father, and of Christ, and of the Holy Ghost; then, that they certainly are not deprived of the sacrament of baptism who are baptized with the most glorious and greatest baptism of blood, concerning which the Lord also said that He had
another baptism to be baptized with. But the same Lord declares in the Gospel, that those who are baptized in their own blood, and sanctified by suffering, are perfected, and obtain the grace of the divine promise, when He speaks to the thief believing and confessing in His very passion, and promises that he should be with Himself in paradise. Wherefore we who are set over the faith and truth ought not to deceive and mislead those who come to the faith and truth, and repent, and beg that their sins should be remitted to them; but to instruct them when corrected by us, and reformed for the kingdom of heaven by celestial discipline.
But some one says,
What, then, shall become of those who in past times, coming from heresy to the Church, were received without baptism? The Lord is able by His mercy to give indulgence, and not to separate from the gifts of His Church those who by simplicity were admitted into the Church, and in the Church have fallen asleep. Nevertheless it does not follow that, because there was error at one time, there must always be error; since it is more fitting for wise and God-fearing men, gladly and without delay to obey the truth when laid open and perceived, than pertinaciously and obstinately to struggle against brethren and fellow priests on behalf of heretics. (Letter 72.22-23)