This is only theoretical. If one, hypothetically, had one or more colleagues who were supposedly English teachers, but who used their influence and time to try to convert their students to Christianity, help prayer meetings in the foreign teachers' office (making non-Christians feel very uncomfortable), had secret Jesus meetings with students, gave students banned books, and did other such things that violate Chinese law, violate their contracts, and generally mislead and trick naive, open students, what could, or should, one do?

you might want to be aware that in some workplaces, some of the (senior) chinese staff is comprised of people who themselves have been converted.

the PSB would be the ones to deal with it but you would have to be 100% sure that you wanted to open that can of worms and maybe have some evidence to support the 'claims'. Hypothetically, they might get away with a warning... it might be very difficult to continue working next to colleagues you had previously informed on. Or as Magnifico pointed out, the management may support them or even be complicit. Maybe just talk to a manager? Would it be possible to have a chat with them directly?

In time students will talk to you about this as well as other staff who are aware o this going on. Yes, this happens, and like you, I don't think it is right. Let it play out and in time intentions will reveal themselves. Do not let this create animosity between you and other staff, in time the students and staff will realize what is going on and slowly put a stop to it. Good Luck!

i could be wrong, but that it's against the law is not a black and white issue. this has been going on for a very long time. even if the contract states no proselytizing, it's often not enforced.

so going to the PSB may not accomplish anything. and if the staff there is supportive of this, then you may need to update your CV soon. or if they find out you're going behind their backs, they can be quite hostile about it and your work environment will become very toxic.

my advice is just avoid them. just be a positive influence on your own students.

or, alternatively .... i worked at a place once with a guy who thought christians were stupid. and he was a loud mouth. he didn't hide the fact that he thought they were stupid and pointed it out every 5 minutes. nothing like hurling insults at people to make friends.

I would hate for anyone to get in trouble or anything like that. I am all for minding one's business and being a good neighbor. I just (hypothetically) would feel sorry for some of the students, who thought they would be learning English, not being converted. I guess here, it is best to just mind to one's own work, yes?

If you like your job, just let it slide. Yunnan is a hotbed for missionaries, so they come and go regardless. Of which, are you sure the management of your school isn't Christian affiliated?

AlexKMG ok thank you. I will do that. I am pretty sure the school itself is 100% secular. I just feel sorry for the students: that is my main concern.

there's no harm in speaking to the students and telling them why you don't agree with the beliefs they're being taught by the missionaries. and then let the students make up their own minds about it.

@neddy
Well, if you're sure...then, bring in a statue of Guanyin, light up some incense, and do some koutou when they have those prayer meetings in your office. You could also attend their bible studies and ask all kinds of annoying questions about the old testament.