Over the past few years, there has been a sharp rise in the number of people who are atheist, agnostic or without religious affiliation. A fifth of all adults and a third of the youngest adults fit into this category.

As secularism becomes more prominent and self-confident, its spokesmen have more insistently argued that secularism should not be seen as an absence — as a lack of faith — but rather as a positive moral creed. Phil Zuckerman, a Pitzer College sociologist, makes this case as fluidly and pleasurably as anybody in his book, "Living the Secular Life."

Zuckerman argues that secular morality is built around individual reason, individual choice and individual responsibility. Instead of relying on some eye in the sky to tell them what to do, secular people reason their way to proper conduct.

Secular people, he argues, value autonomy over groupthink. They deepen their attachment to this world instead of focusing on a next one. They may not be articulate about why they behave as they do, he argues, but they try their best to follow the Golden Rule, to be considerate and empathetic toward others. "Secular morality hinges upon little else than not harming others and helping those in need," Zuckerman writes.

As he describes them, secularists seem like genial, low-key people who have discarded metaphysical prejudices and are now leading peaceful and rewarding lives. But I can't avoid the conclusion that the secular writers are so eager to make the case for their creed, they are minimizing the struggle required to live by it. Consider the tasks a person would have to perform to live secularism well:

• Secular individuals have to build their own moral philosophies. Religious people inherit creeds that have evolved over centuries. Autonomous secular people are called upon to settle on their own individual sacred convictions.

• Secular individuals have to build their own communities. Religions come equipped with covenantal rituals that bind people together, sacred practices that are beyond individual choice. Secular people have to choose their own communities and come up with their own practices to make them meaningful.

• Secular individuals have to build their own Sabbaths. Religious people are commanded to drop worldly concerns. Secular people have to create their own set times for when to pull back and reflect on spiritual matters.

• Secular people have to fashion their own moral motivation. It's not enough to want to be a decent person. You have to be powerfully motivated to behave well. Religious people are motivated by their love for God and their fervent desire to please Him. Secularists have to come up with their own powerful drive that will compel sacrifice and service.

The point is not that secular people should become religious. You either believe in God or you don't. Neither is the point that religious people are better than secular people. That defies social science evidence and common observation. The point is that an age of mass secularization is an age in which millions of people have put unprecedented moral burdens upon themselves. People who don't know how to take up these burdens don't turn bad, but they drift. They suffer from a loss of meaning and an unconscious boredom with their own lives.

One other burden: Past secular creeds were built on the 18th-century enlightenment view of man as an autonomous, rational creature who could reason his way to virtue. The past half-century of cognitive science has shown that creature doesn't exist. We are not really rational animals: Emotions play a central role in decisionmaking, the vast majority of thought is unconscious and our minds are riddled with biases. We are not really autonomous; our actions are powerfully shaped by others in ways we are not even aware of.

It seems to me that if secularism is going to be a positive creed, it can't just speak to the rational aspects of our nature. Secularism has to do for nonbelievers what religion does for believers — arouse the higher emotions, exalt the passions in pursuit of moral action. Christianity doesn't rely just on a mild feeling like empathy; it puts agape at the center of life, a fervent and selfless sacrificial love. Judaism doesn't just value community; it values a covenantal community infused with sacred bonds and chosenness that make the heart strings vibrate. Religions don't just ask believers to respect others; rather, each soul is worthy of the highest dignity because it radiates divine light.

The only secularism that can really arouse moral motivation and impel action is an enchanted secularism, one that puts emotional relations first and autonomy second. I suspect that over the next years secularism will change its face and become hotter and more consuming, less content with mere benevolence, and more responsive to the spiritual urge in each of us, the drive for purity, self-transcendence and sanctification.

David Brooks' column is distributed by the New York Times News Service.