It is when Rev. Ezra Jin says there are about 3,000 underground Protestant church services being celebrated around the Chinese capital on this bright autumn Sunday, that you begin to get an idea of the leap of faith that is happening in this decidedly atheist country.

Rev. Ezra is happily chatting in advance of his second service of the day at Beijing Zion Church, a grandiose name for the series of large and small conference rooms he presides over. They are located above a karaoke bar in an old-fashioned hotel deep in the Beijing suburbs. His is what is called a "house church." It is not sanctioned by the Communist government, hence it is not legal.

But as sometimes happens in China, it is tolerated -- for the moment, anyway.

"For a long time, the government cracked down on house churches. But recently the situation changed," he explained. "It has started to face up to the existence of house churches and make an effort to establish a formal relationship with them."

It's not a perfect situation, he admits, but a vast improvement to what it was. "Ten years ago, house churches, like ours, wouldn't dare to think they could have such a large space to develop," he said.

In recent years, "house" Protestants have been harassed, fined, beaten by police and even jailed for the temerity of shunning the officially sanctioned churches and starting their own.

Several kilometres deeper into the maze of Beijing's suburban sprawl, the Shouwang Church is finishing up the second of its three Sunday services. The congregation of about 250 people is packed into a large boardroom in a medium-rise building that is otherwise full of small companies and offices.

As Rev. Jin Tainming explains it, last year police and government officials mildly hassled him and his congregation, trying to force them to close up shop. But Shouwang members stood firm, so officials tried another tack this year and began pressuring the landlord not to renew the church's lease.

"We were planning to build a church before that," Rev. Tainming explains, "but the new pressure convinced us to accelerate our pace."

Almost half the money for the church has been raised so far.

Estimates range as high as 130 million, but according to Carsten Vala, a specialist in Protestantism in China at Loyola College in Maryland, there are probably about 50 million Christians in China. About 40 million of them are non-denominational Protestants.

There are no divisions into Episcopalian or Baptist or whatever in China. There are simply Christians -- who in Mandarin literally follow "Christ-religion" -- and they are divided into three groups: Catholics, Protestants and Orthodox.

Mr. Vala said the Protestants "tend towards fundamentalism" in their worship, but really are "post-denominational."

He also makes the point that "by and large, Protestants in China are very apolitical."

There are so many college-aged young men waiting for the elevator in the office building where Shouwang Church is located, it looks like a high-tech business must be sharing the floor with the Protestant worshippers. It is an eye-opener when they all head towards the church service.

At both Shouwang and Beijing Zion churches, the congregation is surprisingly young and well educated. It's a phenomenon that is being noted in cities across China, particularly since it is so dramatically different from what has been happening in the countryside where older, working-class congregations formed the backbone of the Protestant house-church movement for many years.

"After 1949 [when the Communist Party came to power], all the old beliefs were cracked apart," he says. "Then there was the Cultural Revolution and the ideals of Communism fell apart, too. So, all Chinese people just

looked to money then. But in fact money couldn't satisfy their spiritual needs."

The breakdown in the national value systems led to "a crisis in belief," he said, a void that religion is increasingly filling for many people.

Rev. Ezra notes that ancient Taoism and Buddhism are also experiencing a revival in China at the moment, but that Christianity, particularly Protestantism, is expanding the fastest of all.

Rev. Ezra was a 21-year-old student of geophysics at the prestigious Peking University in Beijing in 1989 when the troops marched into Tiananmen Square and mowed down the students protesting for democracy. A friend of his was among those killed and for the first time Ezra Jin went to a Christian funeral to pay his last respect.

As he tells it now, the experience changed his life. "I saw people with faith in God and it shocked me."

Rev. Ezra's journey into Christianity led him to the Nanjing Theological Seminary in 1992 and later to advanced theological studies in the United States. Today, Rev. Ezra counts himself among "the first generation of priests in China since the Cultural Revolution."

The bespectacled minister and his fellows, he says, "were mostly young and faced a lot of difficulties, particularly because of the limitations imposed by the government."

But from a congregation of "a dozen people in 2007," Rev. Ezra now boasts 600 parishioners, a Sunday school, a marriage counselling service and a regime to train disciples to help with the parish work.

He is both enthusiastic and optimistic about what the future holds.

"Abroad is in what we call the post-religious era. But it is just the opposite here in China," he said. "When the ideals of Communism were spent after 30 years, religion started to rejuvenate. Today it is an explosion that will last another 20 to 30 years. Religion will incrementally affect all of Chinese society."