The persecution of Christians in China has "intensified" since Pres. Xi Jinping took hold of the Chinese Communist Party's leadership in 2012, a report said.

The report, released last month by U.S. nonprofit organization Freedom House, said the government has tightened its control over religious groups, the effect of which could be felt in the country's "legal, social, political and economic environment."

Christians are not the only ones who undergo intense persecution in China. Falun Gong practitioners, Tibetan Buddhists and the Uighur Muslims also experience "high" or "very high" levels of persecution, the report said.

While in some places in the country, Christians are able to practice their faith without fear of the authorities, there are places where religious restrictions are enforced more strictly. The degree of enforcement varies, depending on the government's perceived threat toward an individual or a church.

Examples of persecution include banning holiday celebrations, using violence and torture and desecrating places of worship. In some instances, local authorities either illegally detain or terminate Christians.

Since 2014, the government has embarked on an intensified crackdown of Christian churches, and many have been affected by its cross removal and church demolition efforts. The government has also arrested human rights lawyers who represent persecuted Christians.  

Authorities also employ "nonviolent forms of control," such as limiting the number of new ministers and teaching twisted religious doctrines.

However, the governments efforts to increase religious restrictions have so far failed to curb the growth of Christian churches, the study said.

Sarah Cook, senior research analyst and author of the report, said the Communist Party's constraints have made it "impossible" for state-sanctioned churches to "meet the growing demand for religion in Chinese society."

Believers in China are also increasingly defying such constraints.

"Believers have responded with a surprising degree of resistance, including in faith communities that have generally enjoyed cooperative relationships with state and party officials," the report stated.

"This escalating cycle of repression and pushback illustrates a fundamental failure of the Chinese authorities' religious policies," the report further said, adding that the tightening control over churches have resulted in an "enormous black market, forcing many believers to operate outside the law and to view the regime as unreasonable, unjust, or illegitimate."

According to Cook, this pattern could eventually lead to the defeat of the Communist Party.

"It reflects the party's difficulty in confronting citizens who are willing to make sacrifices for higher principles," she said, according to VOA News. "From this perspective, it would appear that in the long-term battle for China's spirit, an unreformed Communist Party will ultimately lose."