According to Qian Long, European missionary activities are restricted in China because the Chinese religion is an ancient tradition that doesn't need to change, in other words, he feels that Chinese religion is fine as it is.
The Qianlong Emperor was the sixth man who served as emperor of the Manchu-led Qing dynasty, and the fourth Qing emperor to rule over China proper. He ruled officially from 11 October 1735 to 8 February 1796.