Light is linked with instruction (Isa. 2:5; Ps.119:105,130), truth (Ps 43:3), good (Isa. 5:20), salvation (Ps. 27:1; Isa. 49:6), life (Ps. 36:9; Job 33:28,30), peace (Isa. 45:7), rejoicing (Ps. 97:11), covenant (Isa. 42:6), justice and righteousness (Isa. 59:9), God’s presence and favor (Ps. 44:3; 89:15), or the glory of Yahweh (Isa. 60:1-3).
Apocalyptic visions of the end are associated with the extinguishing of light (Isa. 13:10; Jer. 4:23; Matt. 24:29). In the new age, the new Jerusalem “does not need the sun or the moon to shine on it, because God’s glory illumines it, and its lamp is the lamb”. (Rev. 21:23), (Isa. 60:19; Zech. 14:6-7; Rev. 22:5).
On the first day God created light (Gen. 1:3), which implies that light existed before the sun and other luminaries (Gen. 1:14-18). God Himself is the source of that light (Ps. 104:2; perhaps James 1:17). If so, this light likely signified the divine presence just as the luminous cloud of the Shekinah glory (Exod. 24:15-18; 40:38; 2 Chron. 5:13-14; 7:2).
The indentification of light with the divine presence of the Shekinah glory above sheds light on the meaning of light in the Gosple of John and 1 John. In the person of Jesus “the true light, who gives light to everyone, was coming into the world” (John 1:9). The only begotten God, who is in the bosom of the Father, has made the Father known (John 1:18) because he “became flesh and took up residence among us. We observed His glory, the glory as the One and Only Son from the Father, full of grace and truth” (John 1:14; Exod. 34:6).
Jesus is “the light of the world” and His followers will have “the light of life”, (the truth that beings life; John 8:12). Jesus, who is the light, the embodiment of grace and truth, also brings salvation (John 12:35,46-47) and the doing of God’s works (John 9:4-5). This salvation and doing of God’s works comes from guidance and instruction from the light (John 12:35,47).
Human brings who reject the light are thus rejecting Jesus, the embodiment of grace and truth (John 3:14-21; John 18:37-38, where Pilate apparently exemplifies one who rejects Jesus as the embodiment of truth). John can thus deny that those who do not do the truth have fellowship with God, who is light (John 1:6). 1 John 2:8-10 is entailment of the truth-hating one’s brother is incompatible with the character of both the Father and the Son.
In addition, 1 John 1:7-10 indicates that walking in the light the truth includes the confession of our sins, which keeps us in fellowship with one another and effects cleansing from all sin through the blood of Jesus.
Paul’s use of light in 2 Cor. 4:4-6 runs along parallel lines with John’s usage (cp. Luke 2:32). “Light” (here photismos) is defined as “the gospel of the glory of Christ, who is the image of God” (2 Cor. 4:4). “For God, who said, ‘Light shall shine out of darkness,’” is the One who has “shone in our hearts to give the light (photismos) of the knowledge of God’s glory in the face of Jesus Christ” (2 Cor. 4:6). Indeed, the beholding of the glory of the Lord results in our “being transformed into the same image from glory to glory; this is from the Lord who is the Spirit” (2 Cor. 3:18).
Since they are being conformed to the glorious image of Jesus, who is the embodiment of grace and truth, it is fitting that Christ’s disciples too are called “the light of the world” (Matt. 5:14,16). They have come to Christ to receive life (Eph. 5:13-14) and thus are possessors and givers of light (1 Thess. 5:5; Rom. 13:12; Eph. 5:8; Phil. 2:15; John 5:35). Like Paul (a prototypical disciple), they too are call “to open their [the Jewish people’s and the rest of the nations’] eyes that they may turn from darkness to light and from the power of Satan to God, that they may receive forgiveness of sins and a share among those who are sanctified by faith in Me [Jesus]” (Acts 26:18).
As sons of light, they bear fruit in all goodness, righteousness, and truth (Eph. 5:9) and bring glory to the Father (Matt. 5:16).