New Bibles stream forth from a computerized printing press in this onetime southern capital at a rate of two and a half million a year, for sale to Christians all over China.

Since opening in 1988, the publishing company, a joint venture of the government-approved Protestant Church and a global charity, United Bible Societies, has shipped out 18 million inexpensive Bibles, an astonishing turn in a country that only a few decades ago tried to stamp out religion for good.The Bibles are quickly bought and eagerly used. In downtown Nanjing on any Sunday morning at St. Paul's Church, one of the city's seven legal Protestant churches, the pews overflow with more than 1,000 worshipers at each of two services, while hundreds more watch from another building on closed-circuit television.

With hymns, a sermon, and the closing recitation of the Lord's Prayer, the services here, and at thousands of other churches around the country, have the rhythms of mainstream Protestant services anywhere. Like many urban churches, this one has a preponderance of older women, some of whom were Christian before the communist takeover in 1949, but around the country many men and women, young and old, are embracing Jesus Christ.

Such open, joyous displays of worship were unusual in the 1950s, as the Communists reshaped China, and unthinkable during Mao's Cultural Revolution of 1966-76, when churches were burned and those Christians who were not jailed could only hold clandestine prayer meetings and dared not own a Bible.

Yet even as Bibles flow and churchgoers worship, at least scores of Protestant and Catholic leaders are held in labor camps or jails for refusing to bow to government control. While the confirmed number of imprisoned Christians appears to be lower than is often asserted abroad, their travails are a telling sign that religion here is not truly free.

Just last month, security agents reportedly razed an unapproved Catholic church in Fujian, while in Hebei, to the north, they arrested a pro-Vatican bishop who was too energetically promoting his faith. Last fall, the leader of a fervent born-again sect known as the Weepers was sentenced to a three-year term for disturbing public order.

Millions of other Christians who reject the official church must practice their faith with a wary eye, and even those who embrace the government cannot publicly proclaim or spread their faith as they might wish to.

The charge of religious persecution - of Christians and also of Tibetan Buddhists and some Muslim groups - has emerged as perhaps the most potent human rights issue in Chinese-American relations, one President Clinton cannot avoid as he prepares to visit Beijing.

Clinton is under pressure in Congress to raise the issue. In March, as the House passed a human-rights resolution, Rep. Chris Smith, R-N.J., declared that Beijing's tight control over religion "is totally unacceptable and ought to be condemned."

Critics in the West point to the restrictions and repression as evidence of systematic persecution, while the government's defenders here point, instead, to the relative freedom most Christians now enjoy.

Paradoxically, the rising outcry abroad comes as Christianity in China, especially evangelical Protestantism, is growing explosively. The Rev. Don Argue, recent president of the National Association of Evangelicals in the United States, says China may be experiencing "the single greatest Revival in the history of Christianity."