Make It Count: What Psalm 90 Teaches Us About Time, Wisdom, and Living for God
Life moves fast. Most of us know that, yet we rarely live like it. Psalm 90, written by Moses, forces us to stop and reckon with a truth we tend to avoid: our days are limited, and what we do with them matters more than we think.
Who Wrote Psalm 90 and Why Does It Matter?
Psalm 90 is one of the only psalms in the entire Book of Psalms attributed to Moses. Its superscription reads "A Prayer of Moses, the Man of God."
Moses wasn't writing from a place of abstract theology. He had personally watched an entire generation of Israelites live out the consequences of their rebellion against God. He had seen people come and go. He understood, in a deeply personal way, just how quickly a life can pass.
That lived experience gives this psalm its weight. When Moses writes about generations passing and people returning to dust, he is not being dramatic. He is being honest.
God Is Eternal. We Are Not.
Moses opens the psalm by anchoring everything in the nature of God. He writes:
"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, from everlasting to everlasting, you are God." - Psalm 90:1-2
Notice that Moses does not point to a physical location as home. He points to God Himself. Places change. Generations come and go. But God remains. He was there before the mountains existed, and He will be there long after everything we know has passed.
Then Moses turns the lens on humanity. Verse 3 says God returns man to dust. This language echoes Genesis 3, the moment sin entered the human story and death became part of our reality. Moses places these two realities side by side on purpose: God is everlasting, and humans return to dust.
What Does "A Thousand Years Are Like Yesterday" Really Mean?
Verse 4 says that a thousand years in God's sight are like yesterday once it has passed. This is not a mathematical formula for calculating God's timeline. Moses is using it as an illustration.
A thousand years is an enormous number to us. None of us will ever live that long. But beside an eternal God, even a thousand years is like a day that has already gone by. That is how differently God and humanity relate to time.
We cannot pause time. We cannot store it. We cannot get it back once it is gone. God is not limited by any of that.
How Quickly Does Life Really Pass?
Moses compares human life to grass. In the morning it is fresh and green. By evening, especially under a scorching sun, it is wilted and withered. He is not saying every life ends in a single day. He is showing how brief an entire lifetime looks when placed beside eternity.
James echoes this same truth:
"Yet you do not know what tomorrow will bring. What is your life? For you are a mist that appears for a little time and then vanishes." - James 4:14
Grass. Mist. Different pictures, same reality. Life moves quickly, and most of us already know what that feels like when we look back at old photos or realize how many years have passed since a milestone we remember clearly.
Moses wants us to feel that weight. Not to become depressed about getting older, but to stop treating time as though we have an unlimited supply of it.
What Does Sin Have to Do With the Brevity of Life?
Starting in verse 7, Moses brings sin into the picture. He is not teaching that every person who suffers is being punished for personal sin. He is speaking from a specific context: the Israelites in the wilderness had repeatedly rebelled against God, and they were living with the consequences.
Verse 8 says:
"You have set our iniquities before you, our secret sins in the light of your presence." - Psalm 90:8
We can hide things from the people around us. We can build a convincing outward appearance. But nothing is hidden before God. Our secret sins are in the light of His presence. That makes the brevity of life even more serious. We are not simply people with limited time. We are people with limited time who live before an eternal, all-knowing God.
What Does It Mean to "Number Our Days"?
Verse 12 is the turning point of the entire psalm:
"So teach us to number our days that we may get a heart of wisdom." - Psalm 90:12
Numbering our days does not mean counting how many days you have left. It means recognizing that your days are limited and learning to live with that reality in mind. It means ordering your time and using it wisely.
Paul gives Christians a similar instruction:
"Look carefully then how you walk, not as unwise but as wise, making the best use of the time, because the days are evil." - Ephesians 5:15-16
Moses also asks God to teach Him this. That word matters. This awareness does not come naturally to us. We assume there will always be another year, another opportunity, another Monday morning to get serious about our relationship with God. We tell ourselves we will deal with that sin later, or finally pursue that calling eventually. But we do not know if those opportunities will exist tomorrow.
Biblical wisdom means that what we know about God and what we know about our lives actually shapes the decisions we make every day.
Our Work Is Temporary Unless God Establishes It
In the final verses of Psalm 90, Moses shifts into prayer. He asks God for mercy, for joy, and for restoration. But one request stands out above the rest.
Verse 17 says:
"Let the favor of the Lord our God be upon us, and establish the work of our hands upon us; yes, establish the work of our hands." - Psalm 90:17
Moses knows his hands will eventually stop working. He knows his life will come to an end. But he asks the eternal God to take the work done during that short time and give it lasting value.
You can spend decades working hard at something. You can pour enormous energy into a career, a hobby, or a goal. But Psalm 90 asks a bigger question: was the work you gave yourself to what God was calling you to do, or was it simply what you wanted to do?
Lasting significance has to come from God. That is why Moses does not ask for a bucket list. He asks for God's steadfast love to satisfy Him, and for God to establish whatever work remains.
Why the Resurrection Changes Everything About How We Use Our Time
Moses confronted us with sin, judgment, and death. These are problems that wisdom alone cannot solve. No amount of intelligence or careful planning can undo death.
But Jesus took the judgment our sin deserved. He died in our place and rose from the grave. Because of that, Paul writes:
"Therefore, my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord your labor is not in vain." - 1 Corinthians 15:58
Work done faithfully in the Lord is not wasted. That changes everything about how we think about the days God gives us. We do not have to live desperately trying to prove our significance. We can faithfully use the time we have and trust God to give it lasting value.
The Cell Phone Illustration: What Are You Doing With the Battery You Have Left?
Think about how differently you treat your phone when the battery is at 87% versus when it hits 3%. At 87%, the screen is bright, apps are running, and you have no concerns. At 3%, everything changes. You start making decisions based on what matters most.
The problem is that most of us live our lives at 87%, acting as though the battery will never run out. Moses is asking us to live with the awareness that the battery is limited, not so we become anxious, but so we stop wasting what we have been given.
Here is where the illustration breaks down though. When your phone hits 3%, you can plug it in and recharge it. You cannot do that with your days. The time spent yesterday cannot be recovered tomorrow. But if you are still here, you still have some battery left. The question is what you are going to do with it.
Life Application
Psalm 90 is not meant to leave us feeling hopeless about how quickly life passes. It is meant to wake us up. Moses prayed that God would teach Him to number His days so that He could gain a heart of wisdom. That same prayer is available to you right now.
This week, take one honest look at how you are spending your time. Identify one area where you have been living as though you have unlimited days, whether that is putting off your relationship with God, avoiding a conversation you know you need to have, or delaying a step of obedience you have been putting off. Then take one concrete step in that direction this week.
Ask yourself these questions as you reflect:
If I knew my time was more limited than I assume, what would I stop doing and what would I start doing?
Am I asking God to establish the work of my hands, or am I building something entirely on my own terms?
Is the steadfast love of God the source of my joy, or am I looking for satisfaction in things that will fade?
What is one thing I keep telling myself I will get to eventually that I need to address now?
Make it count. Not because you have to earn your significance, but because the God who is everlasting to everlasting has given you these days as a gift. Use them for Him.