This manual on personal evangelism became a foundational text for the Oxford Group, an non-denominational evangelical movement of the early 20th century whose members included, among others, the co-founders of Alcoholics Anonymous. Evangelicals today will find Soul Surgery full of insight on the ins and outs of personal work. Members of Alcoholics Anonymous will find Walter's book a useful guide to the spiritual foundations of that program. Included as a preface is Henry Drummond's article "Spiritual Diagnosis," from which H. A. Walter drew inspiration for his writing and ministry.