"No one lights a lamp and puts it in the cellar or under a basket, but on a lampstand, so that those who come in may see its light.
Your eye is the lamp of the body. When your eye is good, your whole body is also full of light. But when it is bad, your body is also full of darkness.
Take care then, that the light in you is not darkness.
If therefore your whole body is full of light, with no part of it in darkness, the whole body will be full of light, as when a lamp shines its light on you."