Sermon of the Week: “As Thy Days, so Shall Thy Strength Be.”

Aaron Day June 26, 2023

“As thy days, so shall thy strength be,” Deuteronomy 33:25


As a preacher who struggled with periods of depression, Spurgeon proclaimed the power and grace of God amid spiritual darkness. This strange paradox enabled him to declare, “How much reason have we to bless God for nights! for if it were not for nights how much of beauty never would be discovered…were it not for winter we should never see the glistening crystals of the snow; we should never behold the beauteous festoons of the icicles that hang from the eaves.” For Spurgeon, such times were the reason that God could declare the promise of Deuteronomy 33:25 to his people in their weakness. This is the truth that he sought to bring out in his sermon “As Thy Days, So Shall Thy Strength Be.” Spurgeon understood that “we must shudder at our own trembling weakness, but we still do bless God that we are weak because it makes room for the display of his own invincible strength in fulfilling such a promise as this.”

The Sermon

In the first point, Spurgeon speaks of “the self-weakness hinted at in the text.” Here, he emphasizes that before we have the ability to “behold the brightness of this rich and exceeding promise,” we need, “a good fair idea of the great depth of our own weakness.” Spurgeon describes four contexts in which weakness is most clearly felt: 1) the day of duty, as we our overwhelmed by the work set before us; 2) the day of suffering, as we find ourselves frail and falling to sickness and impatience; 3) the pursuit of spiritual progress, when the Lord seeks to “grow us downward when we are only thinking about going up;” and 4) the time of temptation, when Satan has his arrows trained on the Achilles’s heel of our heart. Spurgeon states that the key declaration of these experiences is that “every child of God will be ready to confess that he is weak.” But God’s people are not left alone in this state.

Spurgeon’s second point is the proclamation of, “the great promise,—‘As thy days, so shall thy strength be.’” For those discouraged by their weaknesses, “this is a well guaranteed promise.” As we see in Job 38-41, we can be confident that God will fulfill His promise because He is omnipotent. But Spurgeon does not make room for his words to be mistaken for a prosperity gospel. There are limits to this promise because, “it says our strength is to be as our days are…not as our desires are.” For Spurgeon, this was a reminder that God’s people need His grace and strength every day of the week, and that God will give His grace to His people according to their needs. Spurgeon further demonstrated that the power of this promise is its omniscient quality. During, “a fine sunshiny morning; all the world is laughing…‘My strength shall be as my day is declares the pilgrim,’” and in, a day of tempest…wherever you may be and whatever trouble awaits you, ‘As thy days, so shall thy strength be.’” It is here the preacher reflects on his own daily weaknesses and the Lord’s supply of strength in the midst of weakness. Spurgeon transitions to his conclusion by staunchly declaring, “You may live till you are never so old, but this promise will outlive you.”

Therefore, Spurgeon concludes with one “inference” or point of application, “Children of the living God be rid of your doubts, be rid of your trouble and fear…your day shall never be more troublesome, or full of temptation, than your strength shall be full of deliverance.” For those in Christ, Spurgeon calls for them to press on in the confidence of God’s strength. But for those who do not know God, Spurgeon warns that their strength is fleeting and in opposition to God, and he called such people to repent lest they not know God’s strength as their own in the day they meet Him.


Spurgeon understood both the pain and beauty seen in the complexity of this life. In the midst of sorrows, he guarded his congregation from despair at its seeming endlessness. And in earthly pleasures, he warned his people not to revel in their own strength. In all this, our confidence should remain fixed in the Lord’s promise, “As thy days, so shall be thy strength.”

Read the sermon here.