Note 39 at Mt. 6:22: Jesus is speaking of spiritual vision. If we keep our attention (eye) single upon Jesus, the Word (Jn. 1:1,14), then all that we will be filled with is the light of His Word (Ps. 119:105). The key to victory is this singleness of purpose (Phil. 3:13). The strength of the laser lies in the fact that all of the light is concentrated on one single point. Likewise, the strength of the Christian lies in how single his vision is upon Jesus, the author and finisher of our faith (Heb. 12:1-3).