Luke 11:34-36

Mace(i) 34 the eye is the light of the body: if therefore your eye be clear, every member of your body will have the benefit of the light: but if it be spoil'd, they must all rest in darkness. 35 take care therefore, that the light which is in thee do not become darkness. 36 for if thy whole body be enlightned, and no part dark, your whole conduct will be regulated, just as the light of a lamp directs all your motions.