John Chin was born April 6, 1911, in Kaifeng, Honan Province, China, and given the name Chin Chung-An, later anglicized to John. His father's name was Chin Yung-hao and his mother's was Yin Shin-yi. Both parents had been converted to Christianity. John attended China Inland Mission church and Sunday school during his youth, and was in public schools during the period of the Nationalists' rule in China. After completing high school, he entered medical school in the 1930s.

While at Honan University, he was chairman of a Christian group on the campus. In 1936, while in medical school, Chin began work in the CIM hospital in Kaifeng. His studies were interrupted in his third year by the war with Japan and the family moved first to Chungking and then to Yunnan province, where Chin transferred to Canton University in that province and finished his training there in 1940. After his graduation from Canton University, he spent two years in a Presbyterian hospital which closed when the Japanese occupied Yunnan province.In 1942, Chin married Wang Ming-hsun, a mission nurse, and he and his wife had one daughter, Chin Wei-ying (Virginia). After the end of World War II, Chin moved his family to Sian (now Xian) in Shensi province to set up a private clinic. While in Sian, he helped to start a Lutheran church and became a licensed pastor to fill in whenever he was not practicing medicine. He continued in these occupations in Sian for two years. Because of Communist activity, the family moved first to Canton and then to Hong Kong after the Communist takeover in China in 1949. In the spring of 1950, the Chins left for Taiwan.

In Taiwan, Dr. Chin became the physician for a government factory and started a church. Several of the members of the church in Sian had come out of China with him, and by 1951 the group was enlarged by seventy-five new baptisms; it became the first Lutheran church in Taiwan. In 1982 this group had spread to include forty new congregations. It was also his hope to begin a seminary to train Chinese-speaking pastors and missionaries and, after a letter-writing campaign, he began a training center for Chinese-speaking persons which became the first Lutheran seminary in Taiwan. He also helped to organize the Hong Kong Lutheran church in 1955. The same year, he left Taiwan and traveled to India and then to Europe, ending his trip by enrolling in the Lutheran seminary in St. Paul, Minnesota.

Dr. Chin returned to Taiwan in 1959, where he worked as a teacher in the Seminary, practiced medicine, and spent several years as a preacher. He retired in 1975 and came to live in the United States where his family had settled.