Sometimes my wife Veronica and I look at each other and say, “How did we both get to be in our 40s already? How do we have two teenagers living in our house?”

Our most recent how-did-I-get-so-old-without-noticing-it moment happened recently while we were watching an old sitcom. It was from the early 80s, and both of us had watched it as teenagers. I started to think about all of the actors and actresses from the show. At the time, they were young and beautiful, full of life and romance. They were the hot people of the day. But I saw a picture of one of those actors in an article recently.

Things have changed.

None of those actors or actresses are nearly as young. They definitely don’t look invincible. They look, well, wrinkly. And then it hit me: The same amount of years has passed for me as these people.

Pretty soon, I guess, I’m not going to be young and beautiful anymore, either.

Paul concludes his letter to the Colossian church by calling them to “[a]ct wisely toward outsiders, making the most of the time” (Colossians 4:5 CSB).

He’s speaking of the kind of wisdom the psalmist prayed for in Psalm 90:12: “Teach us to number our days carefully so that we may develop wisdom in our hearts.” In other words, the wisest way to approach life is to remember the reality of death.

Lord, help me grasp how short life is so I’ll have the right priorities!

It’s the kind of wisdom Paul says that David lived with: “David, after serving God’s purpose in his own generation, fell asleep” (Acts 13:36a). This is what I want said of my life: He fulfilled his purpose and then went to be with Jesus.

When we are young, it seems like life will go on forever. It doesn’t matter how many people tell us otherwise. We all think that way. I did. My kids do. Maybe you do, too.

But here’s the thing: The death rate in America is still holding strong at 100%, and I can tell you life goes by so fast.

It calls me back to the old hymn we used to sing:

Only one life to live, will soon be past; only what’s done for Christ will last.

When we live with the wisdom that makes the most of our short time, then we will prioritize and invest in the only two things that last forever: the Word of God and the souls of people. Acting wisely means being aware of the preciousness of time and the brief moment we have to accomplish our role in it.

Of course, the admonition to act wisely means it’s possible—dangerously possible—to act foolishly.

We act foolishly when we don’t take eternity into account or invest in things that last forever.

We act foolishly when we spend our lives climbing the ladder of success, only to find out it is leaning against the wrong building or providing a comfortable life for ourselves, only to enter eternity with nothing.

We act foolishly when we spend our lives focused on keeping our family close and making them secure and leaving them a big pile of money … but not imparting to them the one thing that really matters: the wisdom that knows that life is not about accumulating stuff but investing in eternity.

Are you acting foolishly, or are you living with wisdom?

When we see the brevity of life—not only see it but feel it in our bones and marrow—things simply cannot remain the same. Our life is a vapor, only moments from dissipating into nothing. It is a mist, soon to disappear.

For those of us who know the gospel, that shouldn’t lead us to despair. It should lead us to urgency. God has only given us a precious few moments, but he has given us the chance to multiply those moments into something that can last eternally.

Only one life to live, will soon be past; only what’s done for Christ will last.