Exhort and Encourage for the Sake of Faith

The author also shows his audience why Israel failed to enter the promised land: they hardened their hearts. The Lord tested them in the wilderness (v. 8) and they failed. The forefathers of the nation failed to keep their hearts God-oriented. Though they saw the “works” of God “for forty years” (v. 9), they put God to the test and rebelled against him.

Israel presumed on God’s kindness. God graciously preserved them for forty years. He delivered them. He kept them alive. He provided manna for them. He guided them through the desert with a pillar of fire by night and a pillar of cloud by day. And yet they presumed on that grace and grumbled against the Lord.

What is the “rest” Israel failed to enter? The word rest in verse 11 refers to the land beyond the Jordan River. God swore in his wrath that the people of Israel would not enter Canaan, the land he had first promised to Abraham and his descendants (Gen 15:18-21). However, the context of the author’s argument indicates that Canaan looked back to the rest of Eden and also typologically foreshadowed the future eschatological rest of the new creation. This is why the writer of Hebrews uses this Psalm and the story of Israel in the wilderness to exhort his readers to remain faithful. He wants them to make it to the true land of rest.

Rest in Scripture metaphorically refers to God’s blessings of safety, security, and salvation. Hebrews develops this picture by bringing a uniquely Christological component to a theology of rest. Hebrews 4 teaches that Jesus Christ is our Sabbath rest. Not a place but a person—Jesus Christ—most fundamentally gives us rest.

The warning in these verses is sobering and serious. Just as he did with Israel, God will shut out from his rest those who rebel, walk in unfaithfulness, and presume on the grace of God. Like faithless Israel, those who presume on the grace of God will die on the wrong side of the Jordan. We must hold firmly today lest we wake up outside God’s eternal rest.

Hebrews 3:12-19

In verses 12-19 the author shifts away from showing his audience Israel’s unbelief to exhorting his audience not to fall into unbelief. He exhorts his people not to follow in first generation Israel’s faithless footsteps. Instead, he encourages them to endure in the faith so that they can enter into God’s eschatological rest.

Verse 12 begins the author’s application of Psalm 95 to his audience. Israel sinned because they did not believe God. They had an “evil, unbelieving heart.” This type of heart ultimately sets us on the path that leads away from the living God. Thus, the author exhorts his brothers and sisters to check their hearts so that they will not end up hard-hearted like Israel.

How do we combat evil, unbelieving hearts? Verse 13 provides the remedy. Christians “encourage each other daily, while it is still called today.” Paul gives the same command to the Colossians when he encourages them to teach and admonish one another “in all wisdom . . . through psalms, hymns, and spiritual songs, singing to God with gratitude in your hearts” (Col 3:16). Immersing oneself in the community of saints, in the care and watchfulness of the local church, in the preaching of God’s Word, and in the exhortation of fellow believers remedies an evil, unbelieving heart. These things protect us from falling away. The author again highlights the urgency of this task. We must immerse ourselves in these things “today.” Tomorrow is no guarantee.

The author also describes an “evil, unbelieving heart” as one that has been hardened by the deceitfulness of sin. The Old Testament diagnoses the hardening of the heart as a terminal disease. A hardened heart leads to eternal death. Each of us at some point had a hard heart, but God, because of his love for us, replaced our hearts of stone with hearts of flesh (Ezek 36:26). While we were dead in our sins and opposed to God, God brought us to life by his grace (Eph 2:1-7). God’s miraculous work on hearts of stone grounds our endurance and helps us fight evil, unbelieving hearts.

The danger of having a hard heart is not just that you might stumble. The danger of a hard heart is that it will lead to a final denial of God and rejection of his grace in Jesus Christ. The danger of a hard heart is unbelief. Hard hearts do not recognize or accept their need for a savior. Therefore, the ministry to which the author exhorts his brothers and sisters is no small ministry. Exhorting brothers and sisters in Christ to watch out for an evil and unbelieving heart is an urgent task for gospel faithfulness with eternal significance.

The “reality that we had at the start,” mentioned in verse 14, is a conversion—one’s first confession of Christ when God regenerated the heart by the power of the gospel. While the author reminds us that God sovereignly ignites our conversion, perseverance in our faith (fueled and motivated by God’s grace) is our responsibility. Ultimately, we cannot keep ourselves. God is the One who began a good work in us and will bring that work to completion in the end (Phil 1:6). God is the One who will uphold and guard us by his power through faith (1 Pet 1:5).

Verses 15 through 18 push forward the author’s argument for perseverance in the faith. In verse 15 the author quotes Psalm 95:7-8 to once again reiterate the importance and urgency of hearing and obeying God’s voice. The questions the author asks in verses 16-18 underline a central theological issue—the fatal error of unbelief. The Israelites committed many sins in the wilderness but only one prevented their entry into the land of promise, the sin of unbelief. Verse 19 powerfully demonstrates the need to persevere in faith. Without faith we will not enter the promised land. The faithless will not enter God’s eschatological rest. The faithful hold firmly until the end.