“Give diligence” is a good translation of this admonition. Diligence is the opposite of “drifting” (Heb. 2:1–3). How do we give diligence? By paying close attention to the Word of God. Israel did not believe God’s Word, so the rebels fell in the wilderness. “So then faith cometh by hearing, and hearing by the Word of God” (Rom. 10:17).

In comparing the Word of God to a sword, the writer is not suggesting that God uses His Word to slaughter the saints! It is true that the Word cuts the heart of sinners with conviction (Acts 5:33; 7:54), and that the Word defeats Satan (Eph. 6:17). The Greek word translated “sword” means “a short sword or dagger.” The emphasis is on the power of the Word to penetrate and expose the inner heart of man. The Word is a “discerner” or “critic.” The Israelites criticized God’s Word instead of allowing the Word to judge them. Consequently, they lost their inheritance.

God uses the Word to enable us to see the sin and unbelief in our own hearts. The Word exposes our hearts; and then, if we trust God, the Word enables our hearts to obey God and claim His promises. This is why each believer should be diligent to apply himself to hear and heed God’s Word. In the Word we see God, and we also see how God sees us. We see ourselves as we really are. This experience enables us to be honest with God, to trust His will, and to obey Him.

All of this is possible because of the finished work of Jesus Christ. (The two “He’s” in Heb. 4:10 refer to Jesus Christ.) God rested when He finished the work of Creation. God’s Son rested when He completed the work of the new creation. We may enter into His rest by trusting His Word and obeying His will. We can do this as we listen to His Word, understand it, trust it, and obey it. Only in this way can we claim our inheritance in Christ.^[1]

^[1] Wiersbe, W. W. (1996). The Bible exposition commentary (Vol. 2, p. 289). Wheaton, IL: Victor Books.