On Oct 31, 1873, Sarah was chosen to serve as a missionary for the Church of Jesus Christ of Latter-day Saints. The program's goal was to have women get medical degrees, study nursing and midwifery, and share their knowledge with other sisters of their wards and stakes. The Relief Society of the Church was in charge of the mission, making Eliza R. Snow the mission President.
Sarah recounts the following:
"Eliza R. Snow came to Richmond to find two women to be sent to Salt Lake to study midwifery. I, Sarah Jane Lewis, and Mrs. Sarah Durney were chosen. When I found I was to go, I said plenty mean things about the ones that thought I could go. I was leaving nine children, the youngest 18-months-old. I thought there were plenty others that could go easier and do better work than I. I decided that I would go to Salt Lake City, visit my sister Julia, wife of Henry Grow, and have a heart to heart talk with President Young; tell him how impossible it would be for me to leave my family. President Young listened to me very patiently, then said, "Sister Lewis, I will give you my blessing—you will stay here the allotted time, study under Romania B. Pratt, your children will be well and happy during your absence. You shall be blessed in your work. When you have a difficult case, call on me, I promise to be with you, above all things have faith.
"Sister Pratt was extra good to me, took me with her to as many of her cases as possible, being with her gave me confidence in myself. My family was well in my absence. On returning home I had the best of luck.... I always lived in settlements where there were no Doctors until Adamson came to Richmond in 1893. I not only attended women but doctored men and children and was never sorry for the knowledge I attained. I always thought of myself as a missionary."
Sarah's great-grandson George E. Bishop records about her:
"It appears that the young doctor had an undying faith and confidence in the blessing of Brigham Young. She afterward related many times that whenever she had a hard case, she never failed to call on President Young for help, and never did she call on him that he didn't give her the strength and confidence to go on.
"From the practice of obstetrics, she branched into other phases of the role of country doctor. The large portion of the rest of her active life she spent caring for the sick. She was always subject to call, day or night. Most of her work she did as a matter of free service, ever sympathetic and on the job. Occasionally a patient was able to pay and when she could, Sarah Jane's "going price" was three dollars for a delivery; never did she receive more than five dollars. It was in the role of doctor, however, that she really made her friends. There were any amount of early Richmond and vicinity families who maintained that Aunt Sarah Lewis could do more to cheer up a patient and relieve suffering than the best doctors imported from the East.
"It is of interest to know that with her other remedies she had a lot of faith in the old “herbs”. In the summer time she would gather tansy, horehound, peppermint, rhubarb-root, and sage. These she would dry and powder then place them in her small black satchel along with the lovers powder, calomel, asafetida, and camphor."
Lydia Malinda Knapp