The Chinese constitution expressly forbids trying to persuade people to take up your religion. It also forbids trying to persuade people to give up their religion. It allows freedom of worship and respects places of worship. Someone going to China as a missionary must have known there was a  criminal element  in his activities, especially after such a long time there. This is not to condone his treatment in prison, so perhaps he should now be working for penal reform in China. Missionaries have a mixed record in China, to say the least. It is not too long ago that missionaries and churches were silent about exporting opium to China (which the Chinese didn't want) in exchange for transportation of pamphlets, missionaries and bibles.