St. Augustine, Letter to Jerome, (415AD), Letter 166:
"Wherefore whosoever tells us that any man can be made alive in the resurrection of the dead otherwise than in Christ, he is to be detested as a pestilent enemy to the common faith. Likewise, whosoever says that those children who depart out of this life without partaking of that sacrament [of Baptism] shall be made alive in Christ, certainly contradicts the apostolic declaration, and condemns the universal Church, in which it is the practice to lose no time and run in haste to administer baptism to infant children, because it is believed, as an indubitable truth, that otherwise they cannot be made alive in Christ. Now he that is not made alive in Christ must necessarily remain under the condemnation, of which the apostle says, that "by the offence of one judgment came upon all men to condemnation." Romans 5:18 That infants are born under the guilt of this offence is believed by the whole Church."
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