Light illuminates and allows one to see. No matter how dark it may be, light dispels the darkness.  Matthew 5:15 tells us, Neither do people light a lamp and put it under a bowl. Instead, they put it on its stand, and it gives light to everyone in the house.  Matthew 6:22goes on to say, The eye is the lamp of the body. If your eyes are healthy, your whole body will be full of light.