The Treason of a Forgetful Heart Text: Psalm 78:40-55
Introduction: The Sin of Amnesia
We live in a rootless age, an age that prides itself on its forgetfulness. We are constantly encouraged to reinvent ourselves, to cast off the old, to live in the perpetual now. But this is not freedom; it is a form of cultural Alzheimer's. A people who do not know where they have come from cannot possibly know where they are going. And what is true for a culture is doubly true for the people of God. The central sin condemned in this psalm, and indeed throughout the Scriptures, is the sin of forgetting. Not a simple, absent-minded slip, but a willful, culpable amnesia. It is the sin of looking at the mighty acts of God, the raw display of His covenant love and power, and then turning away as though you had seen nothing. It is the treason of a forgetful heart.
Psalm 78 is a maschil, a psalm of instruction. It is a history lesson, but not the kind you get in a secular classroom, full of dry dates and morally neutral events. This is history with a point. This is history as covenantal recital, designed to embed the mighty works of God into the memory of the next generation, so that they might not repeat the failures of the last. The psalmist, Asaph, is not just recounting facts; he is delivering a charge. He is laying out the evidence of God's staggering faithfulness against the backdrop of Israel's persistent, thick-headed rebellion.
The section before us today is a case study in this rebellion. It zooms in on the generation of the wilderness, a generation that saw more direct, undeniable miracles than perhaps any other in history, and yet their defining characteristic was faithlessness. They saw the plagues, they walked through the sea, they ate the bread of heaven, and they drank water from a rock. And what was their response? They rebelled, they grieved, they tested, and they pained the Holy One of Israel. Why? The text gives us the root cause with clinical precision: "They did not remember His power." This is the diagnosis of our own age as well. We are surrounded by the goodness of God, the common grace of rain and sun, the special grace of the gospel, the historical grace of our Christian heritage, and we live as practical atheists. We have forgotten. And in forgetting God's works, we have forgotten God Himself.
The Text
How often they rebelled against Him in the wilderness And grieved Him in the wasteland! Again and again they tested God, And pained the Holy One of Israel. They did not remember His power, The day when He redeemed them from the adversary, When He performed His signs in Egypt And His miracles in the field of Zoan, And turned their rivers to blood, And their streams, they could not drink. He sent among them swarms of flies which devoured them, And frogs which destroyed them. He gave also their crops to the grasshopper And the fruit of their labor to the locust. He killed their vines with hailstones And their sycamore trees with frost. He gave over their cattle also to the hailstones And their herds to bolts of lightning. He sent upon them His burning anger, Fury and indignation and distress, A band of destroying angels. He leveled a path for His anger; He did not hold back their soul from death, But gave over their life to the plague, So He struck all the firstborn in Egypt, The first of their vigor in the tents of Ham. But He led forth His own people like sheep And guided them in the wilderness like a flock; He led them safely, so that they did not fear; But the sea covered their enemies. So He brought them to His holy land, To this hill country which His right hand had acquired. He also drove out the nations before them And apportioned them for an inheritance by measurement, And made the tribes of Israel dwell in their tents.
(Psalm 78:40-55 LSB)
The Anatomy of Rebellion (vv. 40-42)
The psalmist begins this section with an exasperated but rhetorical question that highlights the sheer volume of Israel's sin.
"How often they rebelled against Him in the wilderness And grieved Him in the wasteland! Again and again they tested God, And pained the Holy One of Israel. They did not remember His power, The day when He redeemed them from the adversary" (Psalm 78:40-42)
Notice the location: "in the wilderness." This was the place of their total dependence on God. Every meal was a miracle. Every drop of water was a gift. This was not rebellion in a time of plenty, where they might be tempted to think their own hands had gotten them their wealth. This was rebellion in the midst of constant, undeniable, supernatural provision. This is the height of ingratitude. It is like a patient on life support cursing the doctor who is keeping him alive.
The language used to describe God's reaction is intensely personal. They "grieved" Him and "pained" Him. This is anthropomorphic language, to be sure. God does not have passions in the way we do; He is not thrown into emotional turmoil. But this language is meant to teach us something true about the nature of our sin. Our sin is not an impersonal violation of an abstract code. It is a personal affront to our covenant Lord. It is an offense against love. When we sin, we are not just breaking a rule; we are grieving the heart of the One who loves us.
They "tested" God. This is the sin of demanding that God prove Himself on our terms. It's the sin of standing before the Almighty and saying, "Show me a sign, and then I'll believe." But they had already been given signs enough to convince a rock. This testing was not an honest inquiry; it was a hostile cross-examination, born of a fundamentally untrusting heart.
And verse 42 gives us the root of it all: "They did not remember His power." Their rebellion was a function of their amnesia. They forgot the day He redeemed them. The memory of redemption is meant to be the fuel for a life of grateful obedience. When that memory fades, the engine of obedience sputters and dies. This is why the central rite of the New Covenant is a meal of remembrance. "Do this in remembrance of me." We are constitutionally forgetful creatures, and so God has built into our worship the constant, repeated, tangible reminder of our redemption.
The Unforgettable Display (vv. 43-51)
What was it that they forgot? The psalmist now provides a detailed, almost cinematic, highlight reel of the plagues in Egypt. This is not just a random list; it is a polemical assault on the gods of Egypt.
"When He performed His signs in Egypt And His miracles in the field of Zoan, And turned their rivers to blood... He sent among them swarms of flies... frogs... grasshopper... locust... hailstones... frost... bolts of lightning... His burning anger... A band of destroying angels... He struck all the firstborn in Egypt..." (Psalm 78:43-51)
Each plague was a targeted strike against a specific Egyptian deity. The Nile was turned to blood, a direct humiliation of Hapi, the god of the Nile. The frogs, sacred to the goddess Heqet, became a disgusting infestation. The sun, the supreme god Ra, was blotted out by darkness. This was not just a series of unfortunate natural disasters. This was theological warfare. This was Yahweh, the God of Hebrew slaves, systematically dismantling the entire pantheon of the most powerful empire on earth, demonstrating their utter impotence.
The psalmist piles up the language of destruction. God sent "devouring" flies, "destroying" frogs, "burning anger, fury and indignation and distress." He "leveled a path for His anger" and "did not hold back their soul from death." We must not sanitize this. Our modern, sentimental age is deeply uncomfortable with the wrath of God. We want a God who is a celestial teddy bear, always affirming, never judging. But the God of the Bible is the Holy One of Israel. His holiness is a consuming fire against sin. His wrath is not a petty, uncontrolled temper tantrum. It is the settled, righteous, and terrifying opposition of a perfectly holy being to all that is evil. To remove the doctrine of God's wrath is to remove the very thing that makes His grace so astonishing.
The climax of this de-creation of Egypt is the final plague: the death of the firstborn. This was the ultimate blow, striking at the heart of their future, their strength, "the first of their vigor in the tents of Ham." This was the final, unanswerable demonstration that Yahweh alone is God. And it was this very act of devastating judgment on Egypt that was the act of redemption for Israel. The same event was wrath for one and salvation for the other, all depending on which side of the blood of the lamb you were on.
The Unforgettable Distinction (vv. 52-55)
Immediately following this litany of judgment, the psalmist pivots to describe God's tender, pastoral care for His own people. The contrast is jarring and intentional.
"But He led forth His own people like sheep And guided them in the wilderness like a flock; He led them safely, so that they did not fear; But the sea covered their enemies." (Psalm 78:52-53)
While Egypt was being dismantled, Israel was being led. While the Egyptians were drowning in terror, Israel was being led "safely, so that they did not fear." He was their shepherd. This is the doctrine of election on full display. God makes a distinction. He chooses a people for Himself, not because they are better or smarter or more memorable, but simply because He set His love upon them. The same sea that was an instrument of judgment for the Egyptians was a wall of protection for the Israelites. The same God is a consuming fire to His enemies and a loving shepherd to His sheep.
And this pastoral care was not aimless. It had a destination. God's purpose was to bring them to a place.
In verses 54 and 55, we see the fulfillment of the promise:
"So He brought them to His holy land, To this hill country which His right hand had acquired. He also drove out the nations before them And apportioned them for an inheritance by measurement, And made the tribes of Israel dwell in their tents." (Psalm 78:54-55)
God's redemption is never just from something; it is always to something. He redeemed them from bondage in Egypt in order to bring them into an inheritance in Canaan. Notice the language: it is "His holy land," acquired by "His right hand." The land was not won by Israel's military might; it was a gift, acquired by God and given to them. He drove out the nations. He apportioned the inheritance. He made them dwell in their tents. Every step of the process, from the first plague to the final settlement, was an act of sovereign grace.
This is the story they forgot. They forgot the wrath that fell on Egypt. They forgot the grace that fell on them. They forgot the shepherd who led them and the warrior who fought for them. And in forgetting, they fell into rebellion. They traded the glorious memory of their redemption for a bowl of lentils, for a golden calf, for the fleeting pleasures of sin.
Conclusion: Remember the Greater Exodus
This psalm is our story. We are a forgetful people. We have witnessed a far greater display of God's power and a far greater redemption than the one from Egypt. We have seen the ultimate sign, the final miracle, in the field of Golgotha.
In the cross of Jesus Christ, we see the plagues of Egypt magnified to an infinite degree. All the burning anger, fury, and indignation of a holy God against our sin was not just sent upon a band of destroying angels; it was poured out upon His own firstborn Son. God leveled a path for His anger, and He did not hold back His Son's soul from death. Jesus became our Egypt, so that we could become His Israel.
And just as God led His people out from the judgment, He leads us out as well. He has led us out of the bondage of sin and death. He is leading us like a flock through the wilderness of this life. He leads us safely, so that we need not fear, for the sea of God's wrath has already covered our ultimate enemy. And He is bringing us to His holy land, to the inheritance which His right hand has acquired for us, an inheritance that is imperishable, undefiled, and unfading, kept in heaven for us.
The central command for the Christian, then, is to remember. Remember your redemption. Remember the price that was paid. Remember the wrath you were spared. Remember the grace you received. When you are tempted to rebel, when you are tempted to test God, when you are tempted to grumble in your own personal wilderness, the antidote is always the same. You must preach this gospel history to yourself. You must remember His power, the day He redeemed you from the great adversary. Do not be a generation defined by amnesia. Be a people defined by remembrance, and let that grateful memory be the fuel for a lifetime of joyful, faithful obedience.