holy: belonging to God and set apart from common, everyday use, and so pure and worthy of reverence
The first idea in this word is not behavior but ownership: something is holy because God has claimed it, so it is lifted out of common, everyday use and may not be treated as ordinary. Purity comes into it because of whose it is. Since the God who claims it is good and pure, whatever belongs to him is meant to match him.
That one idea covers a wide spread of things the New Testament calls holy.
- God himself, the Holy One, whose holiness is the source of every other use.
- God's own Spirit, named by this word far more often than anything else is.
- Jesus, addressed as the Holy One of God.
- The angels who stand in God's presence and serve him.
- The people God has claimed, called simply the holy ones.
- Places, days, and things dedicated to him: the holy city, the ground at the burning bush, the temple, the covenant, the scriptures.
There is a backstory that explains why one word carries so much. In ordinary Greek this was a rare, minor religious word. Poets and priests reached instead for ἁγνός, "pure," or for ἱερός, used of a temple as a building. Because it was comparatively empty, the ancient Greek translators of the Hebrew scriptures took it up to carry the Hebrew word for holiness (קדושׁ) and filled it with that content. The writers of the New Testament inherited the refilled word, which is why its center of gravity is God rather than ritual.
The most striking New Testament development is the plural used as a name: God's people are "the holy ones," which older English Bibles render "saints." It is not a rank, and not an honor for a few. It is what everyone who belongs to God is called. The New Testament also uses a form of this same word as a name for the sanctuary, the holy place (ἅγιον).
Nuances
Whether the title "the Holy One of God" (Mark 1:24; Luke 4:34; John 6:69) was a known messianic title or only a description of Jesus as the one who belongs to God.
- majorityIt is not a known earlier title. The phrase describes Jesus as God's own and carries no established background, since it is unattested outside these three verses.; Edwin K. Broadhead, Teaching with Authority: Miracles and Christology in the Gospel of Mark
- minorityIt functioned as a messianic title, tying the anointing of the promised king to the name "the holy one."; Max Botner, "The Messiah Is 'the Holy One': ὁ ἅγιος τοῦ θεοῦ as a Messianic Title in Mark 1:24," Journal of Biblical Literature 136.2 (2017): 417-433
Disputed
Whether holiness is at root a negative idea, being separated from the common, or a positive one, belonging to God, and how much weight the traditional separation etymology of the Hebrew root can carry.
- majorityBelonging to God is primary; separation from the common follows from being possessed by him, and the etymology cannot bear much weight.; Walther Eichrodt, Theology of the Old Testament, vol. 1 (London: SCM, 1961); David Peterson, Possessed by God: A New Testament Theology of Sanctification and Holiness (Grand Rapids: Eerdmans, 1995); Jo Bailey Wells, God's Holy People: A Theme in Biblical Theology (Sheffield: Sheffield Academic Press, 2000)
- minoritySeparation is the primary and distinctive idea: what is holy is cut off from ordinary use.; Norman H. Snaith, The Distinctive Ideas of the Old Testament (London: Epworth, 1944)