Direct quotation
Against Julian 3.19.36
Complete ignorance should be understood to be called righteousness, because God said to Abimelech, who was about to lie with Sarah without knowing that she was another man’s wife: “I too knew that you did this with a clean heart” (Genesis 20:6). Thus the condition of those who are born is not harmed by the will of those who conceive them. Even if that will were evil, it would not come within the children’s knowledge in any way.
Infants are born neither righteous nor unrighteous; their own actions will make them so. Infancy is simply rich with the gift of innocence.
A human being is therefore born full of innocence, but capable of virtue, and will deserve praise or blame according to the purpose subsequently chosen.