The Instructor 1.6.33

… and wickedness. The blessed Paul most clearly released us from the inquiry in the first letter to the Corinthians, writing: “Brothers, do not be children in your minds; be infants in evil, but in your minds be perfect.” And the saying, “When I was an infant, I thought as an infant, I spoke as an infant,” hints at his life under the law, in which, not yet as one simple but as one still foolish, thinking childish things he persecuted, and speaking childish things he blasphemed the Word. For “infant” has two meanings. “When I became a man,” Paul says again, “I did away with the things of the infant.” The apostle who confesses that he does away with infancy, banishing it, is not hinting at an immature stage of life, nor at a fixed measure of time, nor at other secret teachings of manly and more perfect lessons; but he calls “infants” those under the law, who are terrified by fear as children are by bogeys, and “men” those who obey the Word and are free: we who have believed, saved by our own free choice, frightened by fear intelligently, not foolishly. The apostle himself will bear witness to this, calling the Jews heirs according to the former covenant, and us heirs according to the promise: “I say,” he says, “that as long as the heir is an infant, he differs in nothing from a slave, though he is lord of all, but is under guardians and stewards until the time set by the father. So we too, when we were infants, were enslaved under the elements of the world; but when the fullness of time came, God sent forth his Son, born of a woman, born under the law, to redeem those under the law, so that we might receive adoption through him.”