The great shrines of Christendom where the Virgin Mary is said to have appeared make some Catholics uneasy.

Writer Flannery o'Connor, for example, went to Lourdes entirely against her inclination. Being anywhere near a hymn-singing, rosary-bearing procession was for her a kind of penance. She claimed that such shrines did little for her devotional life.

She ended up liking the place more than she expected, but many Catholics share her aloofness from this side of Catholic devotion. Aren't pilgrimages a thing of the past? In an age of television, why go to the expense and hassle of traveling to Mexico or Portugal in order to say prayers that we can say anywhere at any time?

Well, I have just returned from Mexico, where I was present for the Feast of Our Lady of Guadalupe, and can report that a pilgrimage is still what it was in the early days of the Church, when western Europe was a veritable grid of pilgrimage routes. It is a way of deepening one's interior life.

The story that Mary appeared to the peasant Juan Diego (now Blessed) in 1531 will provoke in many the reaction of the hero of a Walker Percy novel when someone in the room starts talking about Marian apparitions: “Ah … er … well … I have to be going.”

But no Catholic is required to believe in any supernatural occurrence since the death of the last apostle. Lourdes, Fatima, Guadalupe and the other handful of apparitions approved by the Church are not part of the deposit of faith. Belief in them is in no way necessary for salvation.

At the same time, there is ample reason to give credence to the Church's finding that these apparitions are authentic. At Guadalupe, when asked for a sign that she had truly appeared on the hillside where she asked that a church be built, Mary left her image on the cloak (called a tilma) which Juan Diego was wearing. The tilma still hangs in the Basilica near where the apparition occurred.

No scientist has ever been able to explain how that image managed to get on the tilma (it is not paint) or how the tilma, made of organic cactus fibers which easily disintegrate, is in perfect condition after four centuries. Nor can they explain the miracles which occur now and then. Five years ago, one of the members of my pilgrimage was cured there of terminal bone cancer and has been returning annually since in thanksgiving, bringing other pilgrims with her.

Miracles aside, no reproduction does the image on the tilma justice. I went back and forth on the people mover which takes you past it and could not get enough of it. The Virgin's smile, for one thing, is as enigmatic as that of the Mona Lisa.

Literally millions of Mexicans come to Mexico City, where the shrine is located, for the feast day on Dec. 12. For days, you can see them walking, bicycling, and even jogging from all points down the main roads of Mexico. Many of them are poor, and whole families were huddled in sleep in the open squares around the Basilica. It is a sight to startle those U.S. Catholics who grumble if the Sunday Mass schedule does not precisely fit their schedule of recreations.

Despite their manifest discomforts, all these pilgrims were happy. Observing them, I recalled an insightful remark of the Mexican writer Richard Rodríguez: “Mexico is Catholic and tragic, and everyone there is cheerful. America is Protestant and comic, and everyone seems depressed.”

There are many things that U.S. Catholics can learn from the Mexicans. One is a deeper Marian devotion. The only note of caution is that one not go overboard; there are Catholics who spend more intellectual energy speculating about the so-called third secret of Fatima than they do meditating on the life of Christ.

Another thing we can learn is that Catholicism is a family affair. Many of the pilgrims to the shrine of Guadalupe came as families: grandparents, parents, children. In the United States, we do many things better than the Mexicans, but one thing we do not do well is family life. As a result, many Americans don't know who they are. They have wonderful technological toys and a government that works (more or less), but they don't, as a whole, enjoy the rich family bonds of the Mexicans, and so are impoverished in a way that their southern neighbors are not.

Finally, we can learn from Mexicans the deep spiritual rewards of a pilgrimage. Like any mother, the Virgin of Guadalupe delights in visits from her children. Having just returned from such a visit, I can only offer the words of Robert Hugh Benson, who wrote a beautiful little book about his pilgrimage to Lourdes in 1908: despite all the tourists and shops peddling garish madonnas, these shrines are “soaked, saturated and kindled by the all but sensible presence of the Mother of God.”

New York-based writer George Sim Johnston is author ofDid Darwin Get It Right?