What are the particular traits or characteristics of God's Word that render it so useful a tool and so powerful a weapon in the hand of the Holy Spirit? Hebrews 4:12 and Psalm 19:7–9 address this question directly. From Hebrews 4:12, we learn that God's Word is quick and powerful. From Psalm 19:7–9, we learn that God's Word is perfect and sure; right, pure, and clean; true and righteous altogether.
1. God's Word is quick and powerful.
By quick is meant "living or imbued with life." This life of the Word is no less than the life of God Himself, for as God is, so must His Word be. This life is also power or energy, power harnessed for work. The life of God's Word is ordered and applied to the accomplishment of His purposes: "My word … shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it" (Isa. 55:11). As living seed, God's Word has power to bring forth fruit in the lives of believers, as described in the parable of the sower, where "the seed is the word of God" (Luke 8:11). Because the Word of God "liveth and abideth forever" (1 Peter 1:23), its vitality and potency remain both unexhausted and undiminished through time. Believers discover with Martin Luther that "the Bible is alive, it speaks to me; it has feet, it runs after me; it has hands, it lays hold on me. The Bible is not antique, or modern. It is eternal.
2. God's Word is perfect and sure.
On the one hand, God's Word is perfectly complete. It is everything God intends it to be. This is the organic perfection of the rose and not the mechanical perfection of, say, the internal-combustion engine. The one is perfect and complete at every stage of its unfolding; the other is the result of much trial and error by way of inventive effort. The unfolding history of redemption is also the unfolding history of revelation. At every point, God's Word furnished believers with all they needed for faith and life.
God's Word is also free from any imperfection or blemish introduced by the hand of man. Because it is perfect, God's Word is also sure. As a testimony or witness, it is true and trustworthy. God's Word is sure as a revelation of what man is to believe concerning God and as a rule of what God requires of man. As Jehovah "changeth not" (Mal. 3:6), so His Word stands forever sure as truth unchanging and unchangeable. "For ever, O LORD, thy word is settled in heaven" (Ps. 119:89).
3. God's Word is right, pure, and clean.
Here is the Old Testament statement of the doctrine of biblical inerrancy. The Word is said to be right or straight because it does not deviate from perfect conformity to any just standard by which truth is measurable. The Word is pure as a pure light is clear and bright. Here is a lamp whose flame does not flicker and whose rays pierce to the depths of man's darkness. The Word is clean because it is free from all corruption and from anything that corrupts or defiles.
4. God's Word is true and righteous altogether.
More precisely, God's Word is truth (Ps. 19:9, marginal note; cf. John 17:17). It is a book of truth, with no admixture of falsehood or error. It is likewise a book of righteousness, through and through. It is righteous in what it demands from man as God's creature and servant, righteous in the judgment it pronounces against all ungodliness and unrighteousness of men, and righteous in the promise it holds forth of justification by faith and peace with God through our Lord Jesus Christ.