Tian (Heaven, 天) is a very old idea in Chinese culture. It was important in Chinese stories, ideas and religion a long time ago. During the Shang dynasty (17th to 11th centuries BCE), the Chinese people worshiped a god called Shàngdì, which means "Lord on High". During the Zhou dynasty, the same god was called Tiān. For many centuries, worshiping Heaven was a big part of the official religion in China.
Taoism and Confucianism talk about Tiān (天), which is the part of the universe that is up in the sky, and is often called "Heaven." They also talk about Dì (地), which is the part of the universe that is on the ground and is often called "Earth." These two things are connected and work together.[1]Taoism and Confucianism talk about Tiān and Dì. Tiān is in the sky and is called Heaven. Dì is on the ground and is called Earth. These two parts of the world make up the Three Realms. The middle part is where people live. The lower part is where demons and ghosts are found.[2]
↑Woodhead, Linda; Partridge, Christopher; Kawanami, Hiroko (2016). Religions in the Modern World (Third ed.). New York, NY: Routledge. pp. 147–148. ISBN978-0-415-85881-6.