Psalm 90:12 (NKJV)
12 So teach us to number our days, That we may gain a heart of wisdom.

John Piper tells the story of an old man converted to Christ through the preaching of Piper’s father. Praying for God’s mercy through his tears, the man cried out, “I’ve wasted it. I’ve wasted it.” So little time he had on earth and he hadn’t devoted it to that which truly mattered.

This past week a friend of mine died. He was 48. A week ago Friday we played tennis together; talked about his children; spoke about the weather; sweated on the court; reflected on John Piper’s book Don’t Waste Your Life. By last Sunday morning he had died and gone on to his reward. This side of the grave we won’t meet again.

Blaise Pascal, the great 17th century mathematician, physicist, and Christian apologist, wrote in his Pensees:

Imagine a number of prisoners on death row, some of whom are killed each day in the sight of the others. The remaining ones see their condition is that of their fellows, and looking at each other with grief and despair, await their turn. This is a picture of the human condition…The last scene of the play is bloody, however fine the rest of it. They throw earth over your head, and it is finished forever.

It was this awareness of the transitory nature of life that moved Moses to cry out to God in our psalm today, “So teach us to number our days, That we may gain a heart of wisdom.” When we are confronted with death it is our opportunity to remember that our days are numbered. We will not live forever. God has set our appointed time on earth and when the number of those days comes to a close then our time here will end as well. Because God has numbered our days, Moses asks the Lord to teach us to number them as well. Teach us to count the number of days we have here on earth, to consider that the time we have before death is short.

What is the purpose of this numbering? So that we might have a morbid fascination with death? Dress in black and be morose? Be like the ancient Egyptians, who had a wooden corpse in their homes that they might bring it out in the midst of their parties and show their guests, declaring, “Look on this while you drink, for this will be your lot when you are dead”? Is this why we should learn to number our days?

No. The purpose is so that we may gain a heart of wisdom. What does a heart of wisdom look like? First, it reckons with the vanity of life and the inevitability of death. Pascal notes:

Nothing is of more importance to man than his state, nothing more fearful than eternity. It is unnatural that there should be people who are indifferent to the loss of their life and careless of the peril of an eternity of unhappiness. They react very differently to everything else. They are afraid of the least things that they anticipate and feel. The same person who spends nights and days in a rage, in the agony of despair over the loss of some status or imaginary affront to his reputation, is the same person who knows he will lose everything by death and shows neither concern nor emotion at the prospect. It is extraordinary to see in the same heart and at the same time this concern for the most trivial matters, and yet lack of concern for the greatest.

But the heart of wisdom does not betray this folly. It knows the imperative of reckoning with death, of being ready to face eternity. And so, the heart of wisdom trusts in the sacrifice of Christ on the cross as the only means to reconcile a sinner to a holy God. Nothing in my hand I bring, says the old hymn, simply to Thy cross I cling.

Second, the heart of wisdom lives fully and completely for the glory and grandeur of God. What is the chief end of man? Man’s chief end is to glorify God and to enjoy Him forever. A heart of wisdom knows that we were created to find our great joy and gladness in union and communion with God. And so the man who has learned to number his days has learned to spend every one of them in passionate enjoyment of the Living God.

Unfortunately we often waste our days rather than number them. We move from one day to the next with little thought or reflection, distracted by trinkets rather than devoted to the glory of God. Reminded that we are to number our days, that we are to present to the Lord a heart of wisdom, let us kneel and confess our sins in the Name of Christ.