The Predestination of the Saints/Gift of Perseverance

Therefore it is in vain that it is prescribed to me from that old book of mine, that I may not argue the case as I ought to argue it in respect of infants; and that thence I may not persuade my opponents by the light of a manifest truth, that God's grace is not given according to men's merits. For if, when I began my books concerning Free Will as a layman, and finished them as a presbyter, I still doubted of the condemnation of infants not born again, and of the deliverance of infants that were born again, no one, as I think, would be so unfair and envious as to hinder my progress, and judge that I must continue in that uncertainty.

But it can more correctly be understood that it ought to be believed that I did not doubt in that matter, for the reason that they against whom my purpose was directed seemed to me in such wise to be rebutted, as that whether there was a punishment of original sin in infants, according to the truth, or whether there was not, as some mistaken people think, yet in no degree should such a confusion of the two natures be believed in, to wit, of good and evil, as the error of the Manicheans introduces.

Be it therefore far from us so to forsake the case of infants as to say to ourselves that it is uncertain whether, being regenerated in Christ, if they die in infancy they pass into eternal salvation; but that, not being regenerated, they pass into the second death. Because that which is written, “By one man sin entered into the world, and death by sin, and so death passed upon all men,” cannot be rightly understood in any other manner; nor from that eternal death which is most righteously repaid to sin does any deliver any one, small or great, save He who, for the sake of remitting our sins, both original and personal, died without any sin of His own, either original or personal.

But why some rather than others? Again and again we say, and do not shrink from it, “O man, who are you that repliest against God?” “His judgments are unsearchable, and His ways past finding out.” And let us add this, “Seek not out the things that are too high for you, and search not the things that are above your strength.”