Is God light, holy and just?
When Scripture calls God, or individual Persons of the Godhead, "holy" (as it often does: Lev. 11: 44, 45; Josh. 24:19; 1 Sam. 2:2; Ps. 99:9; Is. 1 :4; 6:3; 41 :14, 16, 20; 57:15; Ezek. 39:7; Amos 4:2; John 17: 11; Acts 5:3, 4, 32; Rev. 15:4), the word signifies everything about God that sets Him apart from us and makes Him an object of awe, adoration, and dread to us.
It covers all aspects of His transcendent greatness and moral perfection, and is characteristic of all His attributes, pointing to the "Godness" of God at every point.
The core of this truth, however, is God's purity that cannot tolerate any form of sin (Hab. 1: 13) and calls sinners to constant self-abasement in His presence (Is. 6:5).
Justice, which means doing in all circumstances things that are right, is one expression of God's holiness. God displays His justice as Lawgiver and Judge, and also as Promise keeper and Pardoner of sin. His moral law, requiring behavior that matches His own, is "holy and righteous and good" (Rom. 7:12).
He judges justly, according to the actual desert (Gen. 18:25; Ps. 7: 11, 96:13; Acts 17:31 ). His wrath, His active judicial hostility to sin, is wholly justified in its manifestations (Rom. 2:5-16), and His particular judgments (retributive punishments) are glorious and praiseworthy (Rev. 16:5, 7; 19:1-4). Whenever God fulfills His covenant commitment by acting to save His people, it is an act of His righteousness, or justice (Is. 51: 5, 6; 56: 1; 63:1; 1 John 1: 9). When God justifies sinners through faith in Christ, He does so on the basis of justice done-the punishment of our sins in the Person of Christ our substitute.
The form taken by His justifying mercy shows Him to be utterly and totally just (Rom. 3:25, 26), and our justification itself is shown to be judicially justified. When John says that God is "light," with no darkness in Him at all, the imagery affirms God's holy purity, which makes fellowship between Him and the willfully unholy impossible, and requires that the pursuit of holiness and righteousness of life be a central concern for Christian people (1 John 1: 5-2: 1; 2 Cor. 6: 14-7: 1; Heb. 12: 10-17).
The summons to believers, regenerate and forgiven as they are, to practice a holiness that will match God's own, and so please Him, is constant in the New Testament, as indeed it was in the Old (Deut. 30:1-10; Eph. 4:17-5:14; 1 Pet. 1: 13-22).