Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.
Then spake Jesus again unto them, saying, I am the light of the world. As the former references to water (John 4:10; John 4:13-14; and John 7:37, etc.) and to bread (John 6:27, etc.) were occasioned by outward occurrences, so possibly may this reference to light have been. For, in "the treasury," where it was spoken (see John 8:20), stood two colossal golden lampstands, on which hung a multitude of lamps, lighted after the evening sacrifice (probably every evening) during the feast of Tabernacles, diffusing their brilliancy, it is said, over all the city. Around these the people danced with great rejoicing. Now, as amidst the festivities of the water from Siloam, Jesus cried, saying, "If any man thirst let him come unto me and drink," so now, amidst the blaze and joyousness of this illumination, He proclaims, "I AM THE LIGHT OF THE WORLD" - plainly in the most absolute sense. For though He gives His disciples the same title (see the note at John 5:14), they are only "light in the Lord" (Ephesians 5:8); and though He calls the Baptist "the burning and shining light" (or 'lamp' of his day-see the note at John 5:35), yet "he was not that Light, but was sent to bear witness of that Light: That was THE TRUE LIGHT which, coming into the world, lighteth every man" (John 1:8-9). Under this magnificent title Messiah was promised of old, Isaiah 42:6; Malachi 4:2, etc.
He that followeth me - as one does a light going before him, and as the Israelites did the pillar of bright cloud in the wilderness,
Shall not walk in darkness, but shall have the light of life - the light as of a new world, the light of a newly awakened spiritual and eternal life.