The Invitation: Take Heed
Take care, brethren, lest there should be in any one of you an evil, unbelieving heart, in falling away from the living God. (3:12)
Based on the illustration of Israel’s unbelief in the wilderness, an appeal is made to the readers of Hebrews not to follow this example. It is a warning against rejecting truth that is known. The judgment of the wilderness days fell on those who rejected God’s Word through Moses, and the warning here is to those who reject God’s Word in Christ. Brethren is not a reference to Christians, as is “holy brethren” in 3:1. It refers to racial brothers, unbelieving Jews, as the term does throughout the book of Acts.
The greatest sin in the world is unbelief. It is the greatest offense against God and brings the greatest harm to ourselves. These readers were informed about the gospel. Many, perhaps, professed to be Christians. None considered himself to be actively, aggressively against Christ; but they all were against Him. No matter how close a person may be to accepting Jesus Christ as Savior, if he never comes to Him, he still has an evil, unbelieving heart. His punishment will be all the more severe because of his knowledge of the living God. If such “have fallen away, it is impossible to renew them again to repentance” (Heb. 6:6). When you have heard the truth of Jesus Christ, when you have acknowledged that it is the truth, and then turn your back and walk away from Him, there is nothing God can do. Once you have heard the gospel and understood its claims, and then say no to Jesus Christ, you have fallen away. You have become apostate.
The Holy Spirit is saying to everyone who hears the gospel: “Respond to Jesus while your heart is still warmed and softened by His truth, while it is still sensitive. Respond to His sweet love and His call of grace. Wait too long and you will find your heart getting hard and insensitive. The decision will become harder and harder as your heart becomes harder and harder. If you continue to follow your evil, unbelieving heart rather than the gospel, you will forever depart from the living God, and forfeit salvation rest.
Turning away from Jesus Christ is not rejecting a religion. Turning away from Jesus Christ is much more than rejecting historical, traditional Christianity. Turning away from Jesus Christ is turning away from the living God. It is turning away from life itself.
12 The general message of the quotation is summed up in a brief second-person exhortation in vv. 12–13, picking up the imperative of Psalm 95:8; from v. 14 the author will revert to his more normal first-person style of “pastoral inclusion” for the remainder of this section. He explains the “hardening of hearts” in the psalm as, literally, “an evil heart of unbelief,” since he traces the failure of the wilderness generation to their refusal to trust God to bring them into the promised land (3:19; 4:2–3). The nature of this unbelief was that they “turned away from” God (apostēnai [GK 695], the root from which we get “apostasy” and which echoes the appeal of Caleb and Joshua to the people in Numbers 14:9 not to be apostatai from God). And the God they turned away from is no less than the “living God”; cf. Jos 3:10, where the successful crossing of the Jordan is proof to the succeeding generation that “the living God is among you.” This powerful title is used sparingly in both the OT and NT, with only fifteen occurrences in each; but four of those are in Hebrews (cf. 9:14; 10:31; 12:22). It speaks of a God who, in contrast both with literal idols and with mere formal ritual, is active and dynamic, a God to be confidently relied on but also a dangerous enemy.
3:12 / The author now begins his commentary, employing key words drawn from the preceding quotation in good midrashic form. The point of the quotation is immediately evident in the words see to it. What is to be avoided at all costs is a heart that is sinful and unbelieving. Heart picks up the same word in verses 8 and 10, where it is described as “hardened” and “going astray.” This is the kind of heart that leads to apostasy, causing one to turn away from the living God. What is in view in this strong language (tō apostēnai, “to apostatize”) is a deliberate rebellion against the truth and therefore against God. The adjective living adds to the perception of the dynamic character of God, who will in no way overlook such action on the part of his children.
12. See to it, brothers, that none of you has a sinful, unbelieving heart that turns away from the living God.
The connection between Hebrews 3:6b and 3:12 is quite natural if we read the lengthy quotation from Psalm 95 as a parenthetical comment. This passage is an illustrative, historical reminder of the obstinate Israelites who died in the desert and were denied entrance to the land God had promised them. The readers are exhorted to hold on to their courage and hope as members of the household of God. They cannot turn their backs on Christ in unbelief, for turning away from Christ is falling away from God.
For Christians, therefore, the experience of the rebellious Israelites must serve as a warning that should not be taken lightly. Christians must thoroughly examine themselves and one another to see whether anyone has a sinful, unbelieving heart.
The author of Hebrews knows from Scripture that a falling away from God finds its origin, development, and impetus in unbelief. Unbelief—characterized by mistrust and unreliability—first comes to expression in disobedience, which in turn results in apostasy. The signs of apostasy are hardening of the heart and an inability to repent (Heb. 3:13; 4:1; 6:6; 10:25–27; 12:15). The following series of contrasts can be made:
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The heart of someone who turns away from God is described as sinful, which means evil or wicked. God does not take the sin of unbelief lightly, for he knows that its origin lies in man’s evil heart. “The heart is deceitful above all things and beyond cure. Who can understand it?” (Jer. 17:9). Furthermore, the author of Hebrews indicates that it is possible to find persons with sinful, unbelieving hearts in the fellowship of the Christian church.
Whoever turns from the living God
It’s he who shares his guilt, his lot
Family, kin, nation, state,
small and great.
Whoever forsakes God is forsaken;
Whoever rejects God is rejected.
Frequent voices daily claim:
Man who’s come of age will settle
But they who say so without God
3:12 The author is definitely speaking to genuine believers. He addresses them as brethren (Gk. adelphoi; compare “holy brethren” in v. 1) as is the uniform treatment throughout the book. Nowhere is there the slightest suggestion that they were mere professors as over against genuine Christians as is widely believed. an evil heart of unbelief: This refers to serious spiritual heart trouble. An unbelieving heart is evil because unbelief is evil. departing (Gk. aphistēmi): This word has the idea of “standing off.” from the living God: Serious losses accrue to unbelieving believers, those who refuse to listen and turn a cold shoulder to God. Evidently this describes a relapse from Christianity into Judaism. Jesus is God. To depart from Him is to depart from the living God. This is contrasted with the “hold fast” of v. 6.
 MacArthur, J. F., Jr. (1983). Hebrews (pp. 91–92). Chicago: Moody Press.
 France, R. T. (2006). Hebrews. In T. Longman III & D. E. Garland (Eds.), The Expositor’s Bible Commentary: Hebrews–Revelation (Revised Edition) (Vol. 13, p. 64). Grand Rapids, MI: Zondervan.
 Hagner, D. A. (2011). Hebrews (p. 65). Grand Rapids, MI: Baker Books.
 Kistemaker, S. J., & Hendriksen, W. (1953–2001). Exposition of Hebrews (Vol. 15, pp. 93–94). Grand Rapids: Baker Book House.
 Radmacher, E. D., Allen, R. B., & House, H. W. (1999). Nelson’s new illustrated Bible commentary (pp. 1639–1640). Nashville: T. Nelson Publishers.