The Arithmetic of Grace: An Old Man's Boast Text: Psalm 71:14-18
Introduction: A Life of Accrued Grace
We live in a culture that worships youth and despises age. We spend billions of dollars trying to hide the fact that we are getting older. We dye our hair, tighten our skin, and pretend that the finish line isn't just over the next rise. The world sees old age as a time of diminishing returns, a slow fade into irrelevance. But the Bible presents a starkly different picture. In the covenant of grace, old age is not a liability; it is a treasury. It is a storehouse of witnessed faithfulness, a long record of answered prayers, and a platform from which to declare the might of God to a generation that desperately needs to hear it.
This psalm is the prayer of an old man, very likely David in his later years. He is surrounded by enemies, his strength is failing, and some are taunting him, saying that God has finally forsaken him (v. 11). This is the final exam for every saint. When your body is weak, when your friends are few, and when the enemy whispers that your whole life of faith has been a sham, where do you turn? What is your boast? The worldling in his old age can only look back with regret or a foolish, fading pride in his own accomplishments. But the saint, the man who has walked with God, has a different kind of memory and a different kind of hope.
The psalmist does not look inward to his own grit or his own track record of faithfulness. He does not tally up his good deeds. Instead, he looks outward and upward to the character and the actions of God. His hope is not in his grip on God, but in God's grip on him. This passage is a master class in godly geriatrics. It teaches us what to do as the years pile up: wait continually, praise increasingly, speak constantly of a righteousness that is not our own, and make it our final ambition to ensure the next generation knows the God who has carried us all our lives.
This is not a quiet retirement. This is a final, glorious offensive. This is the last stand of a man who has learned that his weakness is the perfect theater for displaying the strength of God. And his testimony is not a string of vague platitudes; it is a confident declaration built on a lifetime of experiencing the arithmetic of grace, a salvation so vast he cannot begin to count it.
The Text
But as for me, I will wait continually,
And will praise You yet more and more.
My mouth shall recount Your righteousness
And of Your salvation all day long;
For I do not know the sum of them.
I will come with the mighty deeds of Lord Yahweh;
I will bring to remembrance Your righteousness, Yours alone.
O God, You have taught me from my youth,
And I still declare Your wondrous deeds.
And even when I am old and gray, O God, do not forsake me,
Until I declare Your strength to this generation,
Your might to all who are to come.
(Psalm 71:14-18 LSB)
The Resolve of a Veteran Saint (v. 14)
The psalmist begins this section with a sharp contrast. His enemies are plotting, but as for him, he has a different strategy.
"But as for me, I will wait continually, And will praise You yet more and more." (Psalm 71:14)
The world's answer to trouble is frantic action, anxious scheming, or despairing resignation. The believer's response is to "wait continually." This is not passive thumb-twiddling. The Hebrew word for wait here carries the idea of hope, of eager expectation. It is the posture of a man who knows that God is not slow, but that He has a timetable. To wait continually means to live in a state of perpetual confidence that God will act. It is a settled conviction, not a desperate, last-ditch wish. This is a hope that has been weathered and tested over many decades, and it has proven true every time.
And notice the fruit of this waiting: praise that gets louder, not quieter. "And will praise You yet more and more." Christian praise is not a finite resource. It's not a tank of gas that runs low as the years go by. It is a spring that flows more freely with time. Why? Because every day, every year, provides more evidence of God's faithfulness. The young Christian praises God for the forgiveness of sins, and rightly so. The old Christian praises God for that, plus fifty years of sustained grace, fifty years of deliverance, fifty years of provision. His praise is cumulative. It has weight. It has history. The world thinks that as you get older, you have less to sing about. The saint knows that as he gets older, he has more reasons to sing than he can possibly count.
The Uncountable Salvation (v. 15)
From the resolve to praise, he moves to the content of that praise. What will he talk about?
"My mouth shall recount Your righteousness And of Your salvation all day long; For I do not know the sum of them." (Psalm 71:15 LSB)
His chosen topic is God's righteousness and salvation. This is not an abstract theological discussion group. The word "recount" means to narrate, to tell the story. He is going to be a storyteller, and his story has two main characters: God's perfect justice and God's powerful deliverance. He will tell of how God is always right, and how God always saves. And he will do it "all day long." This is not a quiet-time activity. This is the constant overflow of a grateful heart. It is his breakfast conversation, his midday meditation, and his evening song.
But then he gives the reason for this ceaseless testimony, and it is glorious: "For I do not know the sum of them." He cannot stop talking about God's salvation because he cannot get to the bottom of it. He has been trying to count his blessings his whole life, and he has lost count. This is the arithmetic of grace. You start with your initial salvation, and you think you can put a fence around it. But then God delivers you from a thousand temptations, provides ten thousand meals, rescues you from a hundred foolish decisions, and forgives a million sins. You soon realize that trying to number the acts of God's salvation is like trying to count the stars with a teaspoon. It is innumerable. This is not the lament of a bad bookkeeper; it is the worship of a man overwhelmed by a profligate, spendthrift God who lavishes grace upon grace.
The Exclusive Righteousness (v. 16)
The psalmist now clarifies the foundation of his confidence. Where does this righteousness he speaks of come from?
"I will come with the mighty deeds of Lord Yahweh; I will bring to remembrance Your righteousness, Yours alone." (Psalm 71:16 LSB)
When he approaches God, when he comes into His presence, he does not come bearing his own resume. He doesn't bring a list of his accomplishments or his religious service. He comes "with the mighty deeds of Lord Yahweh." His entrance ticket is what God has done. He walks in clothed in the victories of another.
And then he drives the point home with surgical precision: "I will bring to remembrance Your righteousness, Yours alone." The Hebrew is emphatic: levadekha. Only Yours. This is the heart of the gospel, thousands of years before Paul would write the book of Romans. The psalmist understands that if his standing before God depends on a mixture of God's righteousness and his own, he is doomed. Any righteousness that is not God's righteousness is, by definition, unrighteousness. The poison of autonomy is found in the personal possessive pronouns, mine and ours. The deepest repentance is not for our sins, but for our righteousnesses, which Isaiah tells us are as filthy rags.
This old saint has learned the great secret of the Christian life: the only hope for man is an alien righteousness, a righteousness from outside of himself. It is the righteousness of God, imputed to us through faith. This is why his hope is unshakable. It is not based on his fluctuating performance, but on the unchangeable perfection of God. He is boasting in the Lord, because he has nothing else to boast in.
An Intergenerational Commission (v. 17-18)
Having established his personal hope, his final ambition comes into view. It is not to die peacefully, but to die purposefully.
"O God, You have taught me from my youth, And I still declare Your wondrous deeds. And even when I am old and gray, O God, do not forsake me, Until I declare Your strength to this generation, Your might to all who are to come." (Psalm 71:17-18 LSB)
He begins by acknowledging God as his lifelong teacher. "You have taught me from my youth." True wisdom is not something we discover; it is something that is revealed. God has been his catechist, his tutor, his guide since he was a boy. And the curriculum has been consistent: God's "wondrous deeds." The result is that his declaration has not ceased. The lesson learned in youth is the sermon preached in old age.
This leads to his final, great plea. "And even when I am old and gray, O God, do not forsake me." This is not a cry of doubt, but a prayer of consecration. He is not asking God to preserve his life for his own comfort, but for the sake of his mission. He is asking God to keep him alive and lucid for one great purpose: "Until I declare Your strength to this generation, Your might to all who are to come."
This is the sacred duty of the gray-haired. The covenant is generational. Faithfulness is a baton that must be passed, not a trophy to be buried with the runner. The older generation owes the younger generation a story. Not a story about how tough things were in the old days, but a story about the strength and might of God. They are to be the living historians of God's power, the walking, talking monuments to His faithfulness. This is why a church that segregates its members by age is committing spiritual malpractice. The young need the stories of the old, and the old need the zeal of the young to preach to. The psalmist's greatest fear is not death, but dying before he has finished his testimony, before he has handed over the story of God's mighty acts to the next generation.
Conclusion: Die Empty
This passage is a manifesto against the world's vision of retirement. The world tells you to spend your last years pursuing comfort, leisure, and self-indulgence. God tells you to spend your last years pouring yourself out for the generations to come. The goal is to cross the finish line having spent every last ounce of your testimony.
Your life is a story being written by God. From your youth, He has been teaching you, leading you, and showing you His wondrous deeds. Your salvation is a treasure chest so deep you will never find the bottom. Your righteousness is not your own; it is the perfect, unassailable righteousness of Jesus Christ, given to you as a gift.
Therefore, as the years advance and your hair turns gray, do not retreat. Do not grow quiet. Your voice is needed now more than ever. Your task is to wait on God with ever-increasing hope. Your joy is to praise Him with ever-increasing volume. Your job is to recount His righteousness, the righteousness that is His alone, all day long to anyone who will listen.
And your final prayer should be this: "Lord, don't take me home until I am empty. Don't let me die with an untold story in my heart. Keep me here, give me breath, and give me strength, until I have declared Your might to my children, and my children's children, and to all who are to come." This is how a saint finishes the race. Not by coasting, but by sprinting through the tape, with a shout of praise on his lips.