Adapted from Biblical Doctrine: A Systematic Summary of Bible Truth by John MacArthur.
Becoming More like God
Godliness, Christlikeness, and Christian spirituality all describe a Christian becoming more like God. The most powerful way to effect this change is by letting the Word of God dwell in one richly (Col. 3:16). When one embraces Scripture without reservation, it will energetically work God’s will in the believer’s life (1 Thess. 2:13). The process could be basically defined as follows:
Christian spirituality involves growing to be like God in character and conduct by personally submitting to the transforming work of God’s Word and God’s Spirit.
Holiness Embodies the Very Essence of Christianity
Christians have been saved to be holy and to live holy lives (1 Pet. 1:14–16). What does it mean to be holy? Both the Hebrew and Greek words for “to be holy” (which appear about two thousand times in Scripture) basically mean “to be set aside for something special.” Thus, God is holy in that he sets himself apart from creation, humanity, and all pagan gods by the fact of his deity and sinlessness. That’s why the angels sing of God, “Holy, holy, holy” (Isa. 6:3; Rev. 4:8), and why Scripture declares him to be holy (Ps. 99:9; Isa. 43:15).
Thus, the idea of holiness takes on a spiritual meaning among the people of God based on the holy character of God. For instance, the high priest of God had inscribed across his headpiece “Holy to the Lord” (Ex. 39:30). The high priest was especially set apart by God to intercede on behalf of a sinful nation to a holy God for the forgiveness of their transgressions.
Holiness embodies the very essence of Christianity. The holy Savior has saved sinners to be a holy people (1 Pet. 2:4–10). That’s why one of the most common biblical names for a believer is saint, which simply and wonderfully means “saved and set apart” (Rom. 1:7; 1 Cor. 1:2).
When one considers that a holy God saves, it is no surprise to learn that he gives his Holy Spirit to every believer at salvation. A primary purpose of this gift is to equip believers with the power to live a holy life (1 Thess. 4:7–8; 1 John 3:24; 4:13).
So God wants Christians to share his holiness (Heb. 12:10) and to present themselves as slaves of righteousness, which will result in holiness (Rom. 6:19): “Since we have these promises, beloved, let us cleanse ourselves from every defilement of body and spirit, bringing holiness to completion in the fear of God” (2 Cor. 7:1). Thus the author of Hebrews writes, “Strive for peace with everyone, and for the holiness without which no one will see the Lord” (Heb. 12:14). Holiness is the core of a Christian’s experience.
The Intersection of God’s Word and Holiness
Spiritual maturity springs out of holiness. Scottish theologian John Brown boils holiness down to a definition that we can all understand and pursue:
Holiness does not consist in mystic speculations, enthusiastic fervours, or uncommanded austerities; it consists in thinking as God thinks, and willing as God wills. God’s mind and will are to be known from his word; and, so far as I really understand and believe God’s word, God’s mind becomes my mind, God’s will becomes my will, and according to the measure of my faith, I become holy.1
1. John Brown, Expository Discourses on the First Epistle of Peter (Edinburgh: William Oliphant, 1866), 1:117.