Susan Schultz was born in 1900 into a German farming family of Mountain Lake, Minnesota. After high school, she attended the Moody Bible Institute of Chicago where she graduated from the Bible-Music course in 1926. At Moody she met Loyal Bartel, who graduated from the same course in 1924. He finished MBI's Missionary course in 1925, and then attended Northern Baptist Theological Seminary. He and Susan were married in 1926.

Loyal Bartel had been born in 1901, while his parents were on their voyage via ship to China as first-term missionaries. He was the first of several children to these pioneer missionaries, Henry Cornelius and Nellie Schmidt Bartel, about whom the biography This Mountain Is Mine, by Margaret Epp (Chicago: Moody Press, 1969), was written. Being raised in China, Loyal had decided to return upon the completion of his education in Chicago with his new wife, Susan Bartel. Their denominational conference, the Evangelical Mennonite Brethren (Omaha, Nebraska), assigned them to the China Mennonite Mission Society, and they left for China in December 1927.

The Bartels ministered in the Shantung Province of China for over twenty years with only one furlough taken. (It was spent in Wheaton, Illinois). Loyal served as the leader of a Bible School in Tsaohsien and a preacher. Several times during the Sino-Japanese War Loyal, Susan and their five children were interned by the Japanese. In September 1948, after control of the province had passed to the Communist government, and because of Mrs. Bartel's poor health at the time and the children's need for further schooling, Loyal thought it would be best for his wife to return to the States with the children, while he intended to continue working in China. But the family was never reunited with him in the twenty-three years before his death in China in April 1971.

Mrs. Loyal Bartel returned at first to Mountain Lake, Minnesota, where the family stayed until the three oldest daughters, Lenora, Ruthie, and Lois, graduated from high school. Then the family settled in Wheaton, Illinois, where the remaining two children, Esther and David, finished high school. Mrs. Bartel spent several years employed by Scripture Press in Wheaton, and remained in that community for many years after her retirement. She died on January 10, 2008, just shortly before her 108th birthday.