Henri Nouwen wrote with melancholy about return visits to his boyhood home in the Netherlands, where in one generation vibrant Catholicism had faded into a quaint ritual. A few months before his death, he spoke to a paltry crowd of 36 students at the seminary he had attended, once bustling with hundreds of eager candidates for priesthood.

Nouwen's own devout family had rejoiced in his choice of vocation, though many in the family later lost interest. He was called on to christen a niece or nephew, yet mostly as a cultural relic. "I feel like an entertainer who is far from entertaining," he said after one such event.

On a recent visit to the Low Countries, I encountered many reminders of the decline in European faith. Dutch Christians told me that a century ago, 98 percent of Dutch people attended church regularly; within two generations the percentage fell into the low teens. Today it's under 10 percent. Almost half the church buildings in Holland have been destroyed or converted into restaurants, art galleries, or condominiums.

I attended a vespers service in a Belgian church renowned for its stained glass. Ten of us sat under the high Gothic arches, my wife and I the only ones younger than 70. Outside, far more tourists were complaining about the sign announcing the church's closure to tourists during the service. For a majority of Europeans, the church seems wholly irrelevant.

A German correspondent wrote me about Europeans' reaction to the World Trade Center attacks. American leaders called a National Day of Prayer, and ordinary citizens temporarily flooded churches and purchased Bibles in record numbers. Germans had no comparable response. Instead, on talk shows and editorial pages, they turned introspective: Muslim fanatics ...