Holiness is the quality of being set apart. God is holy because He is like no other, and He exists eternally as the Holy Spirit. God’s holiness includes His moral perfection and righteousness. Persons, places, and things set apart for God are holy rather than common.
The incomparable holiness of God is celebrated throughout the Bible, such as in the Song of Moses and the Prayer of Hannah (Ex 15:11; 1 Sm 2:2). The psalms ring with His holiness. His name or character is to be recognized by all others as holy: “For the High and Exalted One who lives forever, whose name is Holy says this: ‘I live in a high and holy place, and with the oppressed and lowly of spirit, to revive the spirit of the lowly and revive the heart of the oppressed’” (Is 57:15). Because God is holy, His promises must certainly be fulfilled and His judgment against everything unholy is sure (Ps 89:35; Am 4:2).
God is unsearchable and past finding out, inspiring awe and fear. When humans are confronted with God’s holiness, their own unholiness is the more clearly realized, as in the case of Isaiah (Is 6:1-7). All this stands in tension with the personal dimension of God as one seeking to relate to His creatures. God’s holiness (which separates Creator from creation) and His personhood (which makes fellowship possible between the Creator and His creatures) are equally true.
The Book of Leviticus in particular focuses on holiness. God ordered the Israelites to set themselves apart from everything ritually or morally profane: “I am the LORD your God, so you must consecrate yourselves and be holy because I am holy” (Lv 11:44). The Apostle Peter applied this text to God’s new people (1 Pt 1:15-16). See the article on sanctification for more about the holiness of persons.
Because Jesus is fully divine, He has the same holiness that is attributed to God (Lk 1:35; Jn 6:69). Although God’s Spirit worked throughout the Old Testament, He was rarely called the “Holy” Spirit until the birth of Jesus. In Acts and the Epistles, the Spirit gives spiritual life to those who once were unholy and hostile to God. The Holy Spirit lives in all believers, to enable both holy living and good works (Rm 8:9). Christians are frequently called holy ones or saints.
Because God is holy, He will not tolerate ungodliness forever. Divine holiness means that judgment of sin is necessary. God will render a final verdict for all humanity. Everything unholy will be condemned and there will be a new and perfectly holy creation. Peter wrote that “based on His promise, we wait for new heavens and a new earth, where righteousness will dwell” (2 Pt 3:13).