For 41 years, the Notre-Dame-de-Lourdes church was like a second home to George Laplante.

The Catholic church, which dates to 1873, was his spiritual foundation; the congregation, an extended family.

Now, Mr. Laplante, 68, is facing a harsh truth.

"It is sad, it is too bad, but that's the reality of life," he says of news that his Ottawa church will close by the end of this year. "The parishioners who go there cannot keep it going. Our church is fairly old. It is a big monument to look after. There's not enough of us to sustain it."

Mr. Laplante has attended Notre-Dame-de-Lourdes for 41 years. "I raised my kids in that church. Now it is me and my wife. I have to get used to going to another place."

What's happening at Notre-Dame-de-Lourdes-de-Cyrville is a symptom of a larger malaise. Shrinking congregations and spiralling costs are fuelling the decline of the traditional church.

Father Daniel Berniquez, episcopal vicar of the French sector of the Ottawa archdiocese, says churches that once drew 400 to 500 people now attract about 40.

"Fifty years ago, most people went to church," says Mr. Berniquez.

"But that reality has changed. There's less people going to church. It is true for the Catholic church, but it is also true of other denominations."

During the past two years, about 20 churches of various denominations have closed or are slated to close in the area around Ottawa and Gatineau, Que.

Across the country, the United States and Europe, changing demographics, shifting values and growing secularism are taking a toll.

In a British report published two years ago, an independent organization called Christian Research said thousands of churches are closing for lack of practising Christians.

It said more churches are closing than opening. In a warning to church leaders, it predicted that by 2040, 18,000 churches in England will close.

Closer to home, experts say Quebec -- where the Catholic Church once called the shots in public and private life -- stands to lose about half of its 2,000 churches by 2016.

As the mainstream religions wither, the evangelical and Pentecostal denominations are packing in millions of worshippers who seem to have discovered a new path to God.

While the traditional church is still the dominant player in Canada, experts say it must adapt or it will become irrelevant, or die.

"For Catholicism to rely strictly on tradition as though it were bricks at a construction site that you hand over from person to person and generation to generation, that's dead," says Christophe Potworowski, the Kennedy Smith chair of Catholic studies at McGill University.

"There has to be an examination of conscience to see if the church is doing something wrong. A tremendous amount of flexibility in responding to changing circumstances is required."

Father Luc Tardis, rector of the Saint Paul University seminary, agrees.

"Traditional religion has to modify its relationship with the public and with cultural life," Mr. Tardis says.

He notes that not everyone thinks churches respond to their needs or sensitivities. "The big issue is: How much creativity can we bring in to become more relevant for people?"

The numbers show that Canadians have been fleeing the church for decades. In the mid-1940s, about 67% of adult Canadians attended church weekly.

By 1985, the number had plunged to 30%. In 2005, the number hit 20%. In 2006, a Canwest News Service poll found that 17% of Canadians attend church at least once a week, even though about half of those surveyed said they believe in God.

More worrying for churches is the number of young Canadians who are turning their back. In a sweeping study last year by renowned Canadian sociologist Reg Bibby, 47% of the teenagers surveyed said they never go to church. Another 20% said they "hardly ever go," while 21% said they go weekly.

Experts are quick to caution that it does not mean Canadians have given up on faith.

Potworowski suggests it instead reflects a rejection of "organized religion."

Mr. Tardis agrees, but says underlying it all, is a seismic shift in mentality, spirit and values. "People now will say, ‘I am spiritual but not religious.' They will say, ‘I have my own relationship with God and that's it. They have no need or desire to live the religious experience with others, as was the case before."

Unlike today's generation, the early European immigrants, who built many of the churches, found strength and purpose in religion. Attending church on Sunday was a time-honoured tradition. They showed their faith by filling the pews and emptying their pockets.

As older generations passed on, they left behind gaps in the pews and fault lines in church foundations. Their children drifted from the church as values changed, fortunes improved and new interests took hold. Immigration patterns were also changing: A majority of new arrivals were from Asia, the Middle East and Africa, and they practised Islam, Hinduism and Sikhism -- religions that have grown exponentially.

But while traditional churches struggle, new ones are thriving because they've shed rigid dogmas and proclaimed, in the words of one pastor, that the church should be a "hospital for the hurting, not a museum for saints."

Mr. Tardis says Pentecostals can teach the Old Church a thing or two.

"There is a quality of fraternity, spirit of community and warmth that is very attractive," he says. "They have a spiritual fervour, a kind of zeal and passion for God that is expressed in a very charismatic and spontaneous manner, and it pleases people."

Three years ago, many in Cornwall, Ont., shed tears as a shrinking congregation forced the closure of the city's only synagogue. Synagogues in nearby Massena and Malone had closed for similar reasons.

Ottawa Rabbi Reuven Bulka of the Congregation Machzikei Hadas says membership in city synagogues has remained steady, growing fractionally in some cases.

The problem facing the established religions -- Christian, Jewish or Muslim -- is that fixed costs in buildings and maintenance, are growing faster than congregations can sustain.

"Somewhere down the road, because you are not getting enough to pay your fixed costs, you fall into a deficit, which is why, unfortunately, some of the church buildings are closing," Mr. Bulka says.

"This is not the death knell of religion but clearly we have challenges."

Other religions like Hinduism, Sikhism and Islam, however, are growing significantly, fuelled largely by immigration.

In Ottawa, the growth of Islam has led to a building boom in mosques to accommodate expanding congregations. One new mosque has already opened in Gatineau. In about 10 years, it's expected the nation's capital region will boast about a dozen mosques.

Even so, religious experts predict growing secularism will force Islam to confront the same problems that are undermining the churches.

"All religions and cultures have a big challenge in transmitting [their message] to the younger generation," says Mr. Tardis, "all of them will have to deal with it."

The number of Muslims who go to mosque for prayer vary, but according to Ottawa demographer Daood Hamdani, 15% of adult Muslims in the Ottawa region attend mosque every week. Youth attendance is lower.

"The demographics are changing very fast and our people are getting old," says Imam Anver Malam of the Omar Mosque. "The youth are very critical to our future. We are doing everything we can to form a bond with the younger generation early on. We want to give them a reason to come to the mosque." Mr. Malam says.

Mr. Malam says young people experience are struggling to find their place in society. "But we know that we are moving in the right direction."