What is separated from ordinary or profane use is ‘holy’. Hence, above all, God is holy (Isa. 6: 3) and his holiness extends to human beings who have transactions with him (e.g. priests in the Temple) and equipment which they use, and the festivals they celebrate (Lev. 23). The Holiness Code (Lev. 17–26) is a compendium of ritual and moral precepts based on the holiness of God (Lev. 19: 2) and probably used by priests and Levites for instruction.
In the NT the holiness which belonged to the Jerusalem Temple is regarded as a quality of Christian people (1 Cor. 3: 16–17), but pre-eminently Jesus is holy (Luke 1: 35), as he is called in the early preaching (Acts 3: 14), and as he addresses his Father (John 17: 11). Because the Church too is holy (Eph. 2: 19–22), indwelt by the Holy Spirit, any behaviour which violates this relationship is reprehensible (Rom. 5: 5; 2 Cor. 6: 16–7: 1).