As a child of Presbyterian missionaries in China, she was taught the doctrine of Cessationism, which declared that miracles—especially healing—had been temporary for the New Testament Church and then had immediately ceased.
Sanford published her first book, The Healing Light, more than a decade prior to the recognized emergence of the Charismatic Movement, and it is often considered a classic in its field.
Written from a scientific and metaphysical perspective, it appealed to a wide audience by connecting with those seeking a balanced, mediated position.
Agnes became a regular speaker at Camps Farthest Out conferences and has often been referenced by well-known authors, such as Francis MacNutt, John Sandford, and Leanne Payne.
In these respects, Sanford became a significant and foundational part of the Renewal Movement in the first half of the twentieth century.