It's not just other nations that China is spying upon – it is their own people, especially anyone with a faith in anything other than the Chinese state.

Imagine that someone knows that you're reading this article. They know where you're sitting, and who you're with. They know the last thing you looked at on your phone, the last thing you searched for online, the last time you went to meet people. Your moves are watched – not just by cameras in the street, but online too.

That's a little like what life is like for Ming* in China. Digital technology is increasingly being used to target Christians, and surveillance systems are being used to track people's movements and what they do online. It makes following Jesus and sharing the gospel tough – but Ming is determined to do it, no matter the cost.

Big Brother is watching

The issue of being spied upon by the Chinese state has made the headlines this week, as a parliamentary researcher has been arrested and bailed on suspicion of spying for China. The arrest led to PM Rishi Sunak confronting the Chinese Premier Li Qiang at this weekend's G20 summit in Delhi.

According to Gareth Wallace, Director of Advocacy and Public Affairs for the religious persecution charity Open Doors UK & Ireland, surveillance, whether it's of other countries or its own citizens, is almost second nature to the Chinese Communist Party (CCP).

"Surveillance is part of the very fabric of life in China; it has 54% of the world's CCTV cameras," Gareth says. "Nine out of the ten most surveiled cities in the world are in China. In one city there are nearly 120 cameras per 1,000 residents – it's a staggering figure."

Many of these CCTV cameras go much further than any we would encounter on our high streets. They can recognise faces, identify someone's race, even someone's mental and emotional state.

Add to this the fact that Chinese citizens are constantly being tracked by their own mobile devices and through state administered apps, like the Covid tracker, brought in with the pandemic and still operational on phones.

Signs of any untrustworthy or unpatriotic behaviour (such as large unregistered meetings, which can be identified by location trackers on phones) are harshly punished, with a person's "social credit score" being adversely affected – this can prevent people from travelling, receiving any state benefits, or being considered for work.

The penalty that Ming could face for distributing Bibles is far worse than this though. "I could be arrested, interrogated and even imprisoned," he says. "But I knew that God called me to share the gospel by distributing Bibles."

Ming has had to go to great lengths to hide his operations. He would load the Bibles into his car in a hidden alley and send a message to his contacts: "I'm on my way to the old place." 'The old place' is code: he knew that citizens' phones were being monitored. Any wrong word could cost him his freedom.

And one day his fears came true. Ming and his friends were arrested. Miraculously, he was set free – but his friends weren't. To make matters worse, they could no longer use the company that Ming and his fellow believers had worked so hard to set up as a cover for their smuggling.

The arrest put Ming firmly on the radar of the authorities, and they remain determined to restrict his Christian activities. "I knew it would be harder to dodge the police and I'd have to live even more cautiously. I'm [officially] not allowed to attend church or even own a Bible anymore," he says. "At first, every one or two months, the police searched my house." They come less often now, but they still regularly search Ming's home.

The great digital takedown

In one way the current digital explosion should be good news for Ming and the many thousands like him in China. It is possible now to share Bibles and other teaching aids online, and on small memory chips. However, the tentacles of the state are intruding here as well.

"We are not allowed to officially purchase a Bible online," shares Moli*, an Open Doors partner supporting the Chinese church. "Last year, a new regulation that restricts and monitors religious online content was rolled out. Right after that, a lot of religious websites and accounts were blocked or removed, and articles disappeared." She adds that there are ways around this, and Christians are still taking risks to share Christian content and messages.

Indeed, Apple was asked to take down an e-Bible from its app store in China and obliged.

"What is required by the law is an official permit that allows churches to post and share religious content," says another partner, Yangyang*. "Our partners shared that they have received phone calls from authorities warning them to remove their religious content posted online."

Like many Christian communities worldwide, Chinese fellowships were able to take their church life online, with meeting apps like Zoom. However, churches fear that these gatherings are being listened in on too.

Restricting the church

House churches like Ming's are illegal. However, even at the state-approved denominations, such as the Three-Self Patriotic Movement, services and church leaders are rigorously monitored.

"Registered churches have cameras installed," says Moli. "Every week, registered churches must have their sermons reviewed, and adjustments in the content are very likely. Some registered churches are unable to preach the gospel fully."

House churches and small groups– like Ming's – don't have such cameras. But that's because they're illegal in the first place, and so they operate under the radar. "To avoid getting in trouble, house churches divide themselves into small groups," says Moli. "In bigger groups, police might barge in when they receive reports from neighbours."

Learning to trust

As Moli suggests, the threat of surveillance doesn't just come directly from the authorities. There's always the danger that somebody you know will inform on you. After his arrest, Ming struggled with this.

"I had no one to trust," Ming says. "I felt insecure and isolated. I need to make friends cautiously, since there may be spies pretending to be Christians. I need to stay vigilant."

Life for courageous believers like Ming is likely to get harder, as a partner of Open Doors, Yangyang, recognises. "We are definitely entering an era of more restrictions and challenges," she says. However, the technological boom that has brought such heavy surveillance, also offers new opportunities to evade detection and reach more of China with the gospel. Thankfully, China's house church leaders and evangelists like Ming are creative and resourceful – always finding new ways to stand firm in their faith.

While emerging technology provides opportunities for persecution, it may also be used for good. It is vital that international technology companies acknowledge their responsibilities to promote human rights around the world and take measures to ensure that their products are not used for evil ends.

*Name altered for reasons of security.This is an amended version of a story originally produced for www.opendoorsuk.org.