Psalm 90 isn’t very cheerful.
It is Moses’s meditation on the sinfulness and weakness of human life. Perhaps you can imagine an old Moses offering this prayer near the end of his time on earth.
The Psalm title calls him “the man of God.” That reminds us that Moses was the one chosen to lead God’s people out of bondage in Egypt and into the Promised Land. He had witnessed the terrible sufferings of God’s people. He’d experienced God’s mighty acts of deliverance. But Moses had also tasted the bitterness of Israel’s uprisings in the desert and the LORD’s just judgment on his people.
Over all those years, what had Moses learned? He’d learned about sin. About Israel’s sin, and about his own. That even when we have the best of intentions, our inherent weakness can hinder us in doing what’s right. And he had learned that every sinner deserves God’s holy wrath—Moses deserved it too.
In those years Moses also learned about the frailty of life. Think about the thousands of Israelites fallen in the desert: in battle, from snake bites, even consumed by God’s fire. Consider too, the forty years of wandering: God was just waiting for that sinful generation to die off. Wherever they went in the wilderness, the Israelites left graves behind them.
So compared to the everlasting God, Moses sees that mankind is almost nothing: “You carry them away like a flood; they are like a sleep. In the morning they are like grass which grows up: in the morning it flourishes and grows up; in the evening it is cut down and withers” (Ps 90:5-6).
Viewed from one angle, that’s the nature of our existence: nasty, brutish, and short. We are born weak, spend our life sinning, and then we die, each one.
Psalm 90 can seem a bit jarring, especially if we’re optimistic about our life and the prospects of a new year. There’s more here, of course, for there is good news in this psalm, even the gospel of Christ. And it’s in light of everything we know about this life that Moses teaches us to pray in verse 12:
Teach us to number our days.
What is numbering? In a way, it’s as simple as a kindergarten exercise in math. You number the apples, or count the blocks, and you write down the answer. Well, we also have to number our days! But unlike counting apples, this is something we need help with: “Teach us, O God!” We’re not asking God to reveal how long we’re going to live. We pray that God will help us contend with the fact that our days of life are short.
When you’re a kid, of course, time seems to stretch on forever. Two months of summer vacation seem endless! But when you get older, a decade passes by in a flash. Suddenly you’re the senior guy at the office, or all the kids have moved out, and you ask, “Where did the time go?”
But however it feels, for each of us it’s the same: “The days of our lives are seventy years; and if by reason of strength they are eighty years…it is soon cut off, and we fly away” (v. 10). It’s something we need help to acknowledge because we’re probably not inclined to think about it. No one wants to be weak or vulnerable. No one wants to hear the clock ticking.
And what if we don’t think about our limitations? What if we don’t consider the reality of our coming death and what comes afterwards? We’re probably going to be busy living for ourselves, plunging into pleasure and pursuing everything we can accomplish. We won’t think about God’s judgment or the consequences of what we do.
But with a spirit of wisdom we pray, “Teach us to number our days.” Know that this life is delicate. Accept that life will often be difficult. And acknowledge that it’s fleeting. Perhaps you enjoy a measure of stability today—even so, life can change in an instant. Suddenly you’re laid off. You make one very bad decision. A family member gets sick, or you do. The phone rings: there’s been an accident, and someone has died.
We figure that it’d never happen to us: the secure think they will remain secure. Yet the psalm is asking us to consider that things that can radically shift in just a moment. “Teach us to see this, O LORD,” we pray. Because if we’re not ready, what then? If we haven’t served the Lord God and believed in his Son before that moment, what will come of us?
For that’s where the Holy Spirit wants us to go in this Psalm: to the LORD. That’s how it begins, “Lord, you have been our dwelling place in all generations. Before the mountains were brought forth, or ever you had formed the earth and the world, even from everlasting to everlasting, you are God” (vv. 1-2).
The unchanging backdrop for our brief life is the eternity of God. He has lived before all time, He lives through all time, and God will be when time is no more. For us, change occurs with the constant passing of hours and days. Many moments fill each day, each year, and so we get older, and we make progress in one thing, and we decline in another. But if no moments pass for a person, there’s no change. That’s the LORD our God: He is outside time. When the eternal God looks at time, this psalm says, there’s no difference between a day and a thousand years—they’re the same to him. He is everlasting.
So while we number our days, we realize that God has numbered them already. Psalm 139:16 says of the LORD:
In your book they all were written, the days fashioned for me, when as yet there were none of them.
We all know the day of our birth, but the Father already knows the day of our death. And that’s a comfort, for whatever happens, the everlasting God can be our dwelling place.
But the only way that lowly sinners can rest in God is through his gift of atonement. Psalm 90 teaches that all our iniquities are before him and that his anger should consume us—and it will, unless sin is paid for through Christ.
Jesus didn’t live a long life: not 70, not 80. His career lasted only a few years, until in his early thirties He was unjustly executed. If it was anyone else’s life, we’d call that a waste. Yet though it was a short and a difficult life, it had redeeming power. Jesus devoted every hour and day to God’s glory. Then at the end, He tasted the bitterness of God’s anger in our place and was consumed by God’s wrath.
It means that all our years, however many or few, are cleansed with his blood.
All our days, however weak or wasted, can be filled with his power.
Now our life can be renewed by his grace and redirected upwards, for his glory.