This pervasive question is new to Chinese culture. As far as I know, it does not get asked in Taiwan. Where did it come from?
Marxism, since Raymond Aron first pointed it out, has been exposed as having the trappings of a religion. One of the characteristics of Marxism is that it takes its definition of religion from Christianity. Thus despite the fact that Marxism claims to be anti-religion, it defines religion only in Christian terms.
"Do you believe in God? and that...." is a Christian question. Jews, for instance, do not frame religion this way (to Jews it is a series of laws). Neither do Muslims (to Muslims it is an act of submission). Certainly the world's Animists don't focus on this question either.
Chinese Communists use this "do you believe...?" question to subvert all other forms of authority. Chinese religious traditions do not require belief. Use of the term qi does not require belief. The practice and efficacy of any type of medicine does not require belief.
The practice of martial arts, particularly, has absolutely nothing to do with belief. I'll even go further. There is really no such thing as theory. All we have are lists of experiments and protocols for achieving results. The best that can be said about theory is that it is a tool for inventing new experiments. It doesn't have any real world existance.
By the way, everything I have just said is completely compatible with Orthodox Daoism, except that perhaps I've violated the precept "be uncontentious," or another one, "do not comment on the veracity of claims made by (other) cults."
The Chinese world view was first articulated by the founder of Religious Daoism, Zhang Daoling. A thousand years later, during the Song Dynasty it was adopted by the Chinese Government as Orthodoxy. This world view posits that all things and events are mutually self-recreating, there is no external agency. The source of all inspiration and the process by which all inspiration comes into being, is constantly available.
The role of belief in such a world view does not survive Occam's Razor. I bring all this up because it is a constantly reoccurring issue. People often think that belief in qi will somehow improve their Acupuncture treatments. If it works on animals and small children, I think it is fair to say, belief is not a factor.