What, exactly, is God warning us about in Psalm 95? What does it mean to “harden your heart”? The people of Israel continually forgot their salvation: “That was then, this is now.” Yesterday’s grace was for yesterday’s problems, but now I need something for the crisis in front of me. So hardening your heart means turning away from the gospel or leaving it behind in search of more “immediate” saviors.
Structurally, the psalmist celebrates the Lord and calls his people to worship, then hands the microphone to God, who provides the warning. So it would seem accurate that perhaps this was a song of dedication on the occasion of another great deliverance—perhaps the dedication of the second temple after return from exile. And what God is saying is, “Now that I’ve delivered you, don’t make the same mistake that your fathers made after I delivered them. Remember your salvation. Don’t harden your hearts by turning away from it. You are back in the Promised Land—but it’s still possible to be kept out of my rest.”
That seems especially plausible. God had brought them into the Promised Land once, and told them: “Don’t forget what I have done for you.” And then he brought them back from exile and said the same thing: “Remember your salvation.”
To “go astray in your heart” is to wander away from the message of the gospel and begin to fixate on the cares and concerns of this world.
That’s what the Israelites were doing when they came to a place where they were thirsty, and instead of celebrating what their God was going to do, instead of turning to him in joyful anticipation, they talked like this was all hopeless and obviously God had abandoned them.
Everything that generation did wrong—everything from grumbling to commissioning an idol at the foot of Mt. Sinai to refusing to enter the Promised Land—was nothing but a failure and a refusal to remember their salvation.
That’s what it means to harden your heart. That’s what it means to rebel against your God. That’s what it means not to know God’s ways. That’s the heart of idolatry. That’s the source of our cowardice. That’s what turns a church inside out with conflict. That’s what robs our joy and destroys our peace.
We need something to help us because forgetting is so natural to people who are caught in the web of time and loaded down with present cares and worries.
The psalmist and the Lord himself are pleading with the people to resist the hard-heartedness that comes naturally to sinful human beings. And this theme comes to a head in prophecies about Israel’s hardness:
Ezek. 36:26 — “I will remove the heart of stone from your flesh and give you a heart of flesh. I will put my Spirit within you.”