The relationship of image to likeness and likeness to image is reciprocal—a good and noticeable exchange, and a recognizable exchange. Scripture tells us that Adam recognized the atomic design in Eve’s image, and Adam said, “This now is bone of my bones, and flesh of my flesh; she shall be called woman, because she was taken out of man” (Gn 2:23). For the artist of sacred art, image was never an issue of similitude to the actual physical attributes or portraiture but the appearance of a saint as it is transfigured within the likeness to God. In other words, a reunification of image and likeness to God prior to the Fall
But due to original sin, our first parents lost this likeness to God. Did Adam and Eve know the will of God before the Fall? Certainly they knew of God’s will for them not to eat from the tree of knowledge of good and evil. Was their likeness to God their knowledge of the will of God? Was their fear, their nakedness, not only their loss of likeness to God but the loss of their ability to intimately know the will of God? Left without the knowledge of the will of God, without the likeness of God, we retained image and were given free will to choose the will of God and to choose His likeness.
If we are made in the image and likeness of God, then as Christian artists, and in particular as those who make devotional paintings and sculptures, how do we discern image from likeness? The great early Church theologian Saint Irenaeus examined the difference between God’s image and His likeness, and later theologians developed the idea further.
“The image was the human’s natural resemblance to God, the power of reason and will. The likeness was a donum superadditum—a divine gift added to basic human nature. This likeness consisted of the moral qualities of God, whereas the image involved the natural attributes of God. When Adam fell, he lost the likeness, but the image remained fully intact. Humanity as humanity was still complete, but the good and holy being was spoiled. “
 Christian Theology by Millard J. Erickson