We typically think of David as the author of most of the Psalms, but he did not write all of them. Psalm 90 is attributed to Moses, the man of God. It is a prayerful Psalm, and if we want to be considered people of God we would do well to pay attention to this passage of Scripture.
The chapter begins with a tribute to the eternal God. There was never a time when God did not exist, nor will he ever cease to exist. V.2 says, “Before the mountains were born or you brought forth the whole world, from everlasting to everlasting you are God.” We must never forget that we are praying to a God who will always be there, no matter what our circumstances might be.
Then Moses contrasts this eternal God with the humans that he has created. Our lifespan is extremely short, especially when compared to eternity. We are like the new grass that springs up in the morning, but by evening it is dry and withered (v.6). The older we get the faster life goes by, or at least so it seems. Our days “…quickly pass, and we fly away.” (v.10). In light of this truth, Moses prays, “Teach us to number our days, that we may gain a heart of wisdom.” (v.12). When we are younger we tend to think that our days will go on unending. Because of that misconception we make poor decisions and we fail to take advantage of opportunities we have to live lives that are truly significant. A proper understanding of the brevity of life will encourage us to think more deeply and act more intentionally.
This prayer also acknowledges that God is both a God of wrath and a God of grace. V.11 says, “If only we knew the power of your anger! Your wrath is as great as the fear that is your due.” Only by having a proper understanding of how God views our sinfulness can we have a right relationship with a holy God.
God’s grace is seen in his compassion (v.13) and his unfailing love (v.14). We know that God’s great compassion and love are what ultimately led Jesus to die on the cross to pay for our sins.
Some people concentrate too much on the wrath of God and therefore do not appreciate the full joy of his grace. Others go too far in the other direction, turning a deaf ear to the warnings about God’s wrath and only focusing on his grace and mercy. Either extreme is unhealthy; we need to have a complete view of who God is, a view that is informed by Scripture.
The Psalm closes out on an inspirational note— “May the favor of the Lord our God rest on us; establish the work of our hands for us—yes, establish the work of our hands.” (v.17). Here we are reminded that our lives have great meaning. We are doing the work that God has given us to do, and we are doing it in his authority and with the power that he gives us. What an encouraging thought to guide us through our lives!