“Wanna play tag?” DJ asked me.

“Sure—you better run,” I called back.

I let my 10-year-old foster brother get a head start across the pristine lawn. Then I dashed after him, feeling the cool grass brush my bare feet, sucking in summer air and letting my hair stream out behind me. I surged closer to him, reached out, made contact and we both toppled over, grinning and breathing hard.

Wow, I thought. I forgot how much fun it is to run as fast as I can. When was the last time I did this?

For the last several years, I realized, I only ran for exercise. Which is to say, I only ran because I knew I should do something to be physically active. I’d set off at a determined pace, choosing the prettiest path through the neighborhood, with the most energetic music pulsing through my headphones. I’d start to get tired, check the time and see that only five minutes went by. Crap. Another 25 minutes to go until I could put a line through “EXERCISE!!!” on my to-do list.

But this kind of running with my little brother had a different purpose. Well, no, it had no purpose at all. It was running for the sheer thrill of speed, the pleasure of moving through open space as fast as I could go. As an adult, I experienced running only as work. I needed a 10-year-old to remind me that running can also be play.

Children are play experts. They know how to engage in an activity for the pure delight of it. As they grow, they have to learn how to work and accomplish tasks for the sake of necessity. That’s an important part of becoming a responsible adult. But if you’re like me, you might be in danger of becoming a seriously boring adult because you’ve forgotten how to play.

In his lovely book Do Nothing to Change Your Life, Stephen Cottrell recommends “time-wasting strategies” to slow us down and keep us from trying to cram more into our days. Plant a garden and learn the names of each flower. Stand at the stove and stir wine and stock and rice together for 30 minutes to make risotto. Write a letter instead of an email. Do something creative, fun, even frivolous.

Perhaps God was being playful when He designed the 350 kinds of parrots on this planet. Surely it was unnecessary, maybe even excessive, for Him to create the 352,000 species of flowering plants. And what did He want so many galaxies for, with each pinprick of our sky containing thousands of them?

All this abundance doesn’t really accomplish anything. It’s useless, but in the best sense of the word. Useless like chocolate ice cream and Bach’s sonatas and a recurring joke between you and your college friends. Useless like running as fast as you can in a game of tag.

“The world will always be more delicious than it is useful,” writes Robert Farrar Capon in The Supper of the Lamb. God cares about enjoyment, and He doesn’t seem to care about usefulness nearly as much as I do.

Be a hard-working adult. But don’t be a dull, workaholic grown-up. If you find yourself—as I often do—addicted to your to-do list and always fixated on the next task to be done, try keeping the Sabbath. Take advantage of that time to practice the spiritual disciplines of celebration, fun and play. You might be neglecting these practices more than you realize, lured by the idols of achievement, utility and necessity. How boring.

Remember when the disciples asked Jesus who was the greatest in the Kingdom of Heaven? I wonder what they expected Him to say—one of the great heroes of the faith, someone who was a mover and a shaker, someone with an impressive spiritual résumé.

But Jesus surprises them by calling a little child—someone with no achievements, no useful skills. Someone helpless and dependent.

“Unless you change and become like little children,” Jesus tells them, “you will never enter the Kingdom of heaven.”

Work is important and valuable, but it’s not everything. Become a mature adult, but become child-like as Jesus calls you to do. And leave time to play.