I know fiction is a lot more appealing than the truth, TM... but you're completely missing my point. Worshipping God, Jesus, Buddha, or even potato salad is not against the law in China. If it was, there would not be a Catholic church in downtown Beijing.
That woman's arrest was the exception, not the norm.
The (corrupt) police probably felt the woman was an insurgent and just used her religion as an excuse to pull her in so they could bully her. I don't condone it, but the Official Party Line is not anti-religion in any form and there is open, public worship of God. My uncle's a judge in Xuzhou, so trust me... we'd know if it was against the law.