Lent can be a perplexing season. It opens on Ash Wednesday, Feb. 22, with a smudge of ashes on the forehead and the rather bleak reminder from Scripture, “Thou art dust and to dust thou shalt return.”

But reminders of mortality aren’t very popular in a youth-oriented society where wrinkles are seen as horrifying flaws to be removed by costly creams.

As for the topic of death, bring it up in polite conversation and most people will gasp, “Oh, don’t be morbid!”

Still, without facing the obvious fact that our time on earth is limited, we may be tempted to put off spiritual changes indefinitely.

Lent reminds us that we really don’t know when the big clock in the sky will wind down for us. And if there are spiritual tweaks we need to make, we should not postpone them.

In an enlightening DVD titled “Seven Deadly Sins, Seven Lively Virtues,” Father Robert E. Barron, a theologian and author, asks a compelling question: “Are you willing to discipline your desires?” And adds: “If you don’t, they will dominate your life.”

The big question is: Which desires shall I tame? For some people, the sin of gluttony looms large, and Lent is a chance to give up between-meal snacks, or desserts, or breakfast, or all of the above.

For others, Lent is a time to stop obsessive shopping for things we really don’t need.

Still, like all spiritual practices, fasting – whether from feasting or frivolous spending– can be tricky. It’s all too tempting to give up stuff for the wrong reason, as in: “Well, if I quit eating desserts, maybe I can fit into my new jeans by Easter!”

As someone who often gives up sweets during Lent, I can attest to losing a few pounds by Easter Sunday. And that’s a nice side effect of fasting, but not the main point.

The underlying motivation is learning how to better imitate Christ, who told us to pick up our crosses daily and follow him.

This means making sacrifices every day, and that isn’t easy.

Lent beckons us to say “no” in a world where we are constantly being tempted to say “yes.” Advertisers lure us to treat ourselves, whether to fancy lattes, glittering jewelry or trips to elegant islands.

The more we say “yes” to every yearning, however, the harder it becomes to deny ourselves. So during Lent we get a chance to flex the “no” muscle, which can get pretty flabby during the year.

We try forgoing martinis, restaurant outings or shopping until we drop. As a result, we have more money to plunk down in the collection basket for the poor.

During these 40 days, Christians get a chance to learn the biggest and hardest lesson that Christ came to teach us. When we say “no” to ourselves, it becomes easier to say “yes” to someone else.

Lorraine Murray is the author of "The Abbess of Andalusia," a biography of Flannery O'Connor, and two fun-filled mysteries, "Death in the Choir" and "Death of a Liturgist," both set at a small parish in Decatur, Ga. Her email is lorrainevmurray@yahoo.com