1. Thrice in the epistle to the Hebrews, God says: "Harden not your hearts" (3:7,8,15; 4:7).
2. If God had only said it one time that would have been enough, but the fact He says it three times underscores the seriousness of this command.
3. The author of Hebrews is quoting from Psalm 95:7-11.
4. Notice, the author of Hebrews does not say, "Wherefore, as David saith…" or "as the Psalmist saith," but "Wherefore, as the Holy Ghost saith…" (Heb.3:7).
5. This is proof of the verbal inspiration of the Bible. "All scripture is given by inspiration of God" (II Tim.3:16).
6. This also reminds us that this warning comes directly from the Holy Spirit.
7. There is another word I would like for us to look at, and that is the word "Today" (3:7). This word today applied to the Israelites in the wilderness, and now it applies to anyone of us reading it or listening to it being preached. "Today" is for today.
8. In David’s day, when he wrote Psalm 95, it applied to his generation, and 1,000 years later it applied to the original recipients of this epistle. Most importantly, it is for us today.
9. The concept of hardening the heart occurs frequently in the Bible as a description of man’s stubborn refusal to obey God. Once a person adopts a fixed attitude of disobedience to God, their heart gets harder and harder.
10. This hardening was quite evident when the Israelites wandered through the wilderness. The journey from Egypt should have taken a few weeks but because of their rebellious attitude it took 40 years.
11. In the Bible, 40 represents God’s judgment. This epistle was written about AD 64 (Scofield). A few years later, in AD 70, the Roman army invaded Jerusalem and destroyed the city and the temple. It was 40 years since our Lord preached "Repent: for the kingdom of heaven is at hand."
12. But they would not repent. They hardened their hearts. And God allowed the Roman army to destroy their city and to destroy their temple.
13. Today, we will see how God uses the Israelites as an example and a warning to us – a warning about the dangers of hardening our hearts.

I. PEOPLE HARDEN THEIR HEARTS THROUGH TEMPTING GOD (3:9-11).

1. The period when the Israelites wandered through the wilderness is called the "provocation" (Heb.3:8). They provoked God to wrath. They tempted God.
2. The Israelites were the recipients of God’s grace, but they were guilty of ingratitude, murmuring, and disobedience.
3. There are a lot of folks in our churches like that – ungrateful, always murmuring, and often disobedient.
4. The Bible says in verse 9, "When your fathers tempted me, proved me, and saw my works forty years" (cf. Ex.15:22-25; 17:1-7; 32:1-28).
5. God was so highly incensed at their rebelliousness that He decreed that they should wander in the wilderness for "forty years" (Heb. 3:9; cf. Num.14:33,34).
6. Notice that the problem is with the heart, not with the mind.

• "Harden not your hearts…" (Heb.3:8).
• "They do always err in their heart" (Heb.3:10).
• "Take heed, brethren (talking to saved people), lest there be in any of you an evil heart of unbelief…" (Heb.3:12).
• "Harden not your hearts"(Heb.3:15).

II. PEOPLE HARDEN THEIR HEARTS THROUGH UNBELIEF (3:12).

1. Let me make my application: if unbelief prevented most of the Israelites from entering God’s rest (of the adults, only Joshua and Caleb entered the promised land), unbelief will also prevent people today from entering the "rest" God has designed for His people (Heb.3:11,12).
2. Note the words, "To day" (3:7,13,15). God is speaking to us today. And note the word "brethren" (3:12). God is speaking to Christians (3:12-14).
3. Perhaps there is someone here this morning who is wondering: "How can a believer be guilty of unbelief?" It happens all the time! Do you remember the words of the man whose son was demon-possessed? He cried out to Jesus: "Lord, I believe; help thou mine unbelief" (Mark 9:24).
4. Maybe there are some folks like that here today.
5. "How often we trust each other,

And only doubt our Lord.

We take the words of mortals,

And yet distrust God’s Word.

But, oh, what light and glory

Would shine o’er all our days,

If we always would remember

God means just what He says."

6. In the Bible, great stress is placed upon the word "today." None of us is guaranteed tomorrow. We need to live for God "today."
7. But people keep putting God off and playing church and do not realize they are hardening their hearts.

III. PEOPLE HARDEN THEIR HEARTS THROUGH THE DECEITFULNESS OF SIN (3:13).

1. Sin always deceives people. Sin hardens people. Sin blinds people. Sin confuses people. And beloved, sin destroys people.
2. I enjoy reading Aesop’s Fables. One fine summer day a jackass heard some grasshoppers chirping and singing merrily. Delighted with their beautiful music, and hoping to learn the secret of their musical ability, the jackass approached them. "Excuse me, my friends," said Mr. Jackass, "upon what do you feed that makes you sing so sweetly all day long?" The grasshoppers told the jackass that all they ate was dew. The jackass galloped off, determined to maintain the same diet. It wasn’t long before the stupid ass died.
3. What’s the moral of the story? Sin always deceives people and if you let deceive you, you are no better than that stupid jackass!
4. Remember that Satan comes as an angel of light. The lust of the flesh, the lust of the eye, and the pride of life all pull people – even some Christians – away from the things of God.
5. This is why the Bible says to "exhort one another daily" (3:13). But how can you do that when you skip church so much? How can I exhort you when I never see you? How can you enjoy Christian fellowship when you hardly ever come to church?
6. Christian friend: do not be deceived into thinking God can bless you when you are not faithful to His church.
7. Unsaved friend: do not think that you can continue on in your folly without suffering the consequences. John Bunyan wrote: ‘One leak will sink a ship, and one sin will destroy a sinner." Your ship is sinking fast. Soon all will be lost unless you repent and come to Christ.

CONCLUSION:

1. Please allow me to share with you one more of Aesop’s fables. This one is also about a jackass.
2. A farmer was driving his ass along a country lane on the way to town. All of a sudden, the beast decided to leave the beaten path and head for the edge of a precipice which was close to the road.
3. When he was just about on the brink of falling over the cliff, his master ran up and grabbed his tail. He tried with all his might to pull him back but the jackass resisted.
4. Finally, when the man saw it was no use and that he was about to be pulled over the cliff with the ass, he let go of his hold.
5. As the jackass went hurtling over the brink his master cried out after him, "Well, Mr. Jackass, if you want to be the boss, you will have to continue on alone."
6. That’s the same way God feels about it (Heb.3:10-12).