This paper describes the changes that occurred in staff nurses' thoughts and actions when Parse's theory was used as a guide for practice on an acute care medical unit. As participants in an eight month evaluation project of Parse's theory, nurses struggled to change in a process of growth which led to new approaches in practice. Ways of thinking about patients and practice before and after Parse's theory clarify how this approach is different from the traditional biomedical model. Nurses describe how their perspective of human beings changed from viewing patients as problems to viewing patients as unique individuals. Healing nurse-person relationships led to enhanced satisfaction and morale for nurses and improved quality of care for patients. This article offers challenging ideas for all nurses interested in testing nursing theory and in particular for nurses interested in Parse's humanistic approach.