Isaiah 40: They That Wait Upon the Lord Shall Renew Their Strength

There is a tiredness sleep does not fix — the weariness of carrying things too long, of running on empty, of a soul that has simply run out. Isaiah 40 was written to a people exactly that exhausted, worn down and afraid God had forgotten them. Its closing promise is one of the most quoted in the Bible, and it has a surprise at its center: the way to new strength is not to try harder, but to wait.

The God who does not grow tired (v.28)

Hast thou not known? hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is weary?

Before Isaiah says a word about your strength, he says something about God’s. The Creator of the ends of the earth fainteth not, neither is weary. The God you are leaning on tonight has never once been tired. He did not run low yesterday and he will not run low while you sleep. The very weariness you feel is something he simply does not have — which means there is an inexhaustible supply to draw from, held by One who never needs to rest from holding it.

There is no searching of his understanding, Isaiah adds. Even when you cannot trace what God is doing, the limit is in your sight, not in his wisdom.

Strength for the empty (v.29)

He giveth power to the faint; and to them that have no might he increaseth strength.

Notice who receives. Not the strong — the faint. Not those with reserves left — them that have no might. This is grace running exactly opposite to how the world measures. The qualification for God’s strength is not that you have enough of your own; it is that you have run out. If you are empty tonight, you are not disqualified. You are precisely the one this verse is for.

Even the young fall (v.30)

Even the youths shall faint and be weary, and the young men shall utterly fall.

Isaiah is honest: the strongest human strength has a bottom. The youngest, fittest, most energetic utterly fall eventually. So if you have hit the end of yours, you have not failed in some unique way — you have discovered what is true of every human being. Self-made strength always runs out. That is not a flaw to fix; it is an invitation to a different source.

The secret is waiting (v.31)

But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint.

Here is the turn the exhausted heart needs. The renewed strength does not come to those who grit their teeth and push. It comes to those who wait upon the Lord — the Hebrew qavah, to wait with hope, like a rope wound tight with expectation. To wait on God is to stop trying to generate your own strength and to receive his instead.

And see the order of the images: mount up… run… walk. We expect it to climb — walk, then run, then fly. Instead it descends, and that is the mercy. There are days for soaring. But the final, quietest promise is for the hardest days: they shall walk, and not faint. When you cannot fly or run, when all you can do is put one foot in front of the other — even then, waiting on him, you will not collapse. He gives strength sized exactly to the day you are in.

To rest in tonight

You do not have to find strength for tomorrow tonight. You only have to wait on the One who never runs out.

The everlasting God fainteth not. He giveth power to the faint. They that wait upon the Lord shall renew their strength. I shall walk, and not faint.

Lay down the effort of holding yourself up. Wait on him in the dark, and let strength be given to you, new, by morning.

Lord, I am tired in a way that sleep alone won’t mend, and I have come to the end of my own strength. You never grow weary — so tonight I stop striving and simply wait on you. Renew what is spent in me, and give me strength enough for tomorrow’s walking. Amen.