St. Irenaeus stated that God did not create human beings “perfect” at the outset, and he offered various reasons why.
He suggested, for instance, that Adam and Eve, whom he depicts as infants in paradise, needed to grow in order to achieve perfection, the fullness of being human to which they were called by God. For example, a mother could give a newborn child meat rather than milk, though this would not benefit the infant at all. Likewise, God could have given us a full share in his life and existence from the beginning—but we would not have been able to receive such a magnificent gift, without being prepared by learning through experience.
A newborn infant may have “perfect” limbs, but needs to exercise (and to fall) before being able to walk and to run; so, too, creatures need to be exercised in virtue before they can share in the uncreated life of God.
John Behr. Becoming Human: Meditations on Christian Anthropology in Word and Image (Yonkers, NY: St. Vladimir’s Seminary Press, 2013), 58-9.