No One is Reconciled to God Except Through Christ.
On the Merits and Forgiveness of Sins, and on the Baptism of Infants · Saint Augustine of Hippo
Taking into account all the inspired statements which I have quoted,—whether I regard the value of each passage one by one, or combine their united testimony in an accumulated witness or even include similar passages which I have not adduced,—there can be nothing discovered, but that which the catholic Church holds, in her dutiful vigilance against all profane novelties: that every man is separated from God, except those who are reconciled to God through Christ the Mediator; and that no one can be separated from God, except by sins, which alone cause separation; that there is, therefore, no reconciliation except by the remission of sins, through the one grace of the most merciful Saviour,—through the one sacrifice of the most veritable Priest; and that none who are born of the woman, that trusted the serpent and so was corrupted through desire, are delivered from the body of this death, except by the Son of the virgin who believed the angel and so conceived without desire.
Merit 2.57.1