Matthew 6:22-23 KJV
22 The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light. 23 But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness!
I have to be honest-these verses had me stumped. Even after looking up in the original Greek, I'm still not sure I completely understand.
What I have pulled from these verses goes along with how we look at life. If we look at life with a biblical worldview, then we will be in union (single) with the truth and we will see clearly and it will affect our whole life. However, if we look with a worldly worldview, we will not see clearly because it will be dark and the darkness will keep us from seeing the truth.