Hebrews 4:5-8 (ESV)
And again in this passage he said,
“They shall not enter my rest.”
 Since therefore it remains for some to enter it, and those who formerly received the good news failed to enter because of disobedience,  again he appoints a certain day, “Today,” saying through David so long afterward, in the words already quoted,
“Today, if you hear his voice,
do not harden your hearts.”
 For if Joshua had given them rest, God would not have spoken of another day later on.
The passage of Scripture that the writer to the Hebrews quotes in Hebrews 4:3, 5 and 7 is from Psalm 95. In that Psalm an invitation to enter God’s rest is given. There is a sense of urgency in the Psalm for it says “Today, do not harden your hearts…”
The point Hebrews 4 makes here is that the rest the Psalmist is talking about cannot be the Promised Land because the Promised Land has been inhabited by Israel for about 400 years by the time the Psalm is written. The rest the Psalmist refers to is something other than the rest Joshua got after he conquered the land. What is it?
It is Christ.
If God’s rest on the seventh day points to the eternal rest we get in Christ; and if the rest that Joshua got when he conquered the land is not the rest that God has promised us but points to Christ; and if the Psalmist wanted his readers to receive something better than what they were chasing after and that was Christ; then we should know that what we need more than anything else is Christ.
People get tired and cranky and are always looking for something that will better them. They chase after religion, sex, education, power, money. They want peace and security and happiness and contentment.
And they want rest.
But they seek in all the wrong places for it and get frustrated in their searching. One of the ironies of this is that they never seem to equate their frustration with the search. It never seems to occur to them that the problem might be that they are chasing the wrong things.
A man chased after a million dollars. When it did not make him happy he chased after two million and then three and a billion. His faithfulness to his god would be laudable if not so ridiculous. But we see this kind of thing all the time. The drug addict who knows that what he really needs is more of the same. The young man chasing women seeks more and more perverse thrills. The religious person makes greater and greater demands on himself in the hopes that this will bring him the peace with his god that he is seeking.
The Jews sought land, a king, a political messiah. Some turned to Christ and now that life has turned hard they are considering turning back to Judaism. “Why?” asks the author of this letter. “You have the One that all the old covenant points to. The Psalmist tells you to find your rest in Christ.”
Dear Christian, rest comes from Christ. It comes to those who trust in Him. He gives rest from the work of seeking to find oneself acceptable to God. You are already as acceptable to God as you can be because of Christ. If you lack peace be like the greedy millionaire who thinks that he just needs more money. Except with you, you know that the problem is not Jesus. The problem is you. You need to grow closer to Christ. You need to understand the Gospel better than you do. You need to walk with Him in faithfulness. You need to hear Him. He is the Creator of all that exists. There is nowhere else to look than Him. Today, do not harden your heart. He is here and He grants rest.