I Am The Light Of The World.
Then Jesus spoke to them again, saying, "I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life." John 8:12 NKJV
A great doctrine laid down, with the application of it.
The doctrine is, That Christ is the light of the world: Then spoke Jesus again unto them; though he had spoken a great deal to them to little purpose, and what he had said was opposed, yet he spoke again, for he speaketh once, yea, twice. They had turned a deaf ear to what he said, and yet he spoke again to them, saying, I am the light of the world. Note, Jesus Christ is the light of the world. One of the rabbies saith, Light is the name of the Messiah, as it is written, Dan. 2:22, And light dwelleth with him. God is light, and Christ is the image of the invisible God; God of gods, Light of lights. He was expected to be a light to enlighten the Gentiles (Lu. 2:32), and so the light of the world, and not of the Jewish church only. The visible light of the world is the sun, and Christ is the Sun of righteousness. One sun enlightens the whole world, so does one Christ, and there needs no more. Christ in calling himself the light expresses, What he is in himself-most excellent and glorious. What he is to the world-the fountain of light, enlightening every man. What a dungeon would the world be without the sun! So would it be without Christ by whom light came into the world, ch. 3:19.
The inference from this doctrine is, He that followeth me, as a traveller follows the light in a dark night, shall not walk in darkness, but shall have the light of life. If Christ be the light, then, It is our duty to follow him, to submit ourselves to his guidance, and in every thing take directions from him, in the way that leads to happiness. Many follow false lights-ignes fatui, that lead them to destruction; but Christ is the true light. It is not enough to look at this light, and to gaze upon it, but we must follow it, believe in it, and walk in it, for it is a light to our feet, not our eyes only. It is the happiness of those who follow Christ that they shall not walk in darkness. They shall not be left destitute of those instructions in the way of truth which are necessary to keep them from destroying error, and those directions in the way of duty which are necessary to keep them from damning sin. They shall have the light of life, that knowledge and enjoyment of God which will be to them the light of spiritual life in this world and of everlasting life in the other world, where there will be no death nor darkness. Follow Christ, and we shall undoubtedly be happy in both worlds. Follow Christ, and we shall follow him to heaven. - Matthew Henry