People believe that their health is related to religion
People think if do evil will come home to roost, they believe in karma, also believe in reincarnation. They think if done evil things, the Buddha will all punishment happen on their own, they will be stubborn, that cannot be cured.
In the qing dynasty, Buddhism thought has been deeply rooted in the hearts of the people, people believe that god has high strength mana, believe that god will always be in the sky, watching them. If do anything bad or I'm not happy, god will get sick.