Pope Francis didn't make global headlines on Aug. 14, 2014, when -- with permission from Communist Party leaders -- Shepherd One flew through Chinese airspace on the way to Seoul, South Korea.

Still, it was a symbolic moment that hinted at progress, after decades of bitter persecution for Chinese Catholics loyal to the Vatican. Then, a year later, Bishop Zhang Yinlin was ordained as bishop of Anyang, after nods of approval from both Rome and Beijing.

So things are looking up for religious freedom in China?

If so, what did it mean when the Rev. Gu Yuese -- leader of the largest Protestant megachurch in China's state-approved Three-Self Patriotic Movement -- was recently jailed after opposing the government's demolition of thousands of crosses in "China's Jerusalem," part of Zhejiang province.

"There may be all kinds of reasons they arrested him, other than that he is famous and his church is huge. It's hard to know what's happening, when you're talking about the Chinese government," said Rodney Stark, co-director of the Institute for Studies of Religion at Baylor University. He is the author or co-author of 36 books on various religious issues, past and present, including "A Star in the East: The Rise of Christianity in China," with sociologist Xiuhua Wang.

"We can say that we haven't seen the Nero effect yet, with the government putting heat on Christians because China's economic numbers are looking bad. … Also, it's important to remember that we've reached the point where many leaders in China now have kids who are Christians. In some villages, you may have a Communist Party leader with a cross on his wall."

The bottom line: There is truth in the popular saying that China is so huge and complex that just about anything someone says about religion in China will be true -- somewhere in China.

At the same time, it's crucial to understand that human-rights trends among the 1.38 billion people in China, even among minority groups, will have a major impact on world affairs.