They are there to intercept the wrong person coming in. This is not to protect any religious mysteries; Mormonism
is not a particularly secretive faith and usually seeks out new converts, but because if a Chinese passerby were to join the service, it could mean all those taking part were breaking the law.
There are only five state-sanctioned religious associations in China, all under the tight control of the Communist Party. Others walk a delicate legal tightrope, with the threat of a crackdown always hanging over their heads. While the government tolerates foreigners practicing their religion and attending services together, it takes a hard line against anything approaching proselytising or missionary work, a prohibition the Mormon Church takes seriously.
"We have to ask to see if they have a foreign passport to attend," said Jason, a lifelong member of the Church who worked in Shanghai for almost a decade until relocating back to the United State in 2018. "I have frequently been this person watching the doors and on many occasions I have sadly had to turn away Chinese citizens who wished to worship with us."
And that is during the good times. In recent years, the Chinese government has increased its regulation of religious worship, launched crackdowns against underground churches and instituted new restrictions on those faiths which operate in the grey area of only catering to foreigners.
So the Church's announcement on April 5, that it plans
to open a temple in Shanghai, the first ever in mainland China, was seen by some as a bold decision.
The Church claims it won't change anything, but the idea that a US church with expansion in its DNA could open an official temple in China is likely to be controversial -- and may not be allowed by Beijing. Already, authorities in Shanghai have suggested that the announcement was made without their prior approval, even as experts said the Church would likely never have revealed the plans without a clear go ahead.
In Salt Lake City, Utah, the spiritual headquarters of the US-based Church, Jason "could hardly believe" the news.
"I couldn't have imagined that we would ever have a temple in Shanghai at this time," he said. "Immediately, my WeChat started lighting up as we were all expressing joy and excitement with our China friends."
Jason is a pseudonym. Like several other current members of the Church interviewed for this story, he requested anonymity to speak about its functioning in China without the permission of Church leadership.
The Church of Jesus Christ of Latter-day Saints declined multiple requests for an interview for this story, referring CNN to a website about its operations in China
and President Russell Nelson's statement on April 5.