John 8:12

The light of the world [τ ο φ ω ς τ ο υ κ ο σ μ ο υ]. Not lucnov, a lamp, as John the Baptist (v. 35). Light is another of John's characteristic terms and ideas, playing a most important part in his writings, as related to the manifestation of Jesus and His work upon men. He comes from God, who is light (1 John 1:5). "In Him was life, and the life was the light of men" (i. 4). The Word was among men as light before the incarnation (i. 9; John 9:5), and light came with the incarnation (iii. 19 - 21; John 8:12; John 12:46). Christ is light through the illuminating energy of the Spirit (xiv. 21, 26; John 16:13; 1 John 2:20; 1 John 2:27), which is received through love (xiv. 22, 23). The object of Christ's work is to make men sons of light (xii. 36, 46), and to endow them with the light of life (viii. 12).

In ver. 20, we are told that Jesus spake these words in the Treasury. This was in the Court of the Women, the most public part of the temple. Four golden candelabra stood there, each with four golden bowls, each one filled from a pitcher of oil by a youth of priestly descent. These were lighted on the first night of the Feast of Tabernacles. It is not unlikely that they may have suggested our Lord's figure, but the figure itself was familiar both from prophecy and from tradition. According to tradition, Light was one of the names of the Messiah. See Isaiah 9:1; Isaiah 42:6; Isaiah 49:6; Isaiah 60:1-3; Malachi 4:2; Luke 2:32.

Walk in darkness [π ε ρ ι π ε τ η σ ε ι ε ν τ η σ κ ο τ ι α]. This phrase is peculiar to the Gospel and First Epistle.

Shall have [ε ξ ε ι]. Not only shall see it, but shall possess it. Hence Christ's disciples are the light of the world (Matthew 5:14). Compare lights, or, properly, luminaries [φ ω σ τ η ρ ε ς] a name, applied to believers in Philippians 2:15.