The idea of the eye being a light for the body is the image of the Spirit of Christ in one's heart pointing the way in which to go. When Jesus calls the eye the light of the body, he charges that it is not the hands, or the feet, or the belly which directs the body to walk. Instead it is the mind or the soul that inspires action. No part of the human body can operate without that the mind acted first. Therefore, as the heart goes, so does the body. If the heart is dark, then the actions of the body will follow. But if the heart is in the light of Christ, then the actions themselves will be illuminated in the brightness of God's eternal glory!