This project, conducted during the COVID-19 pandemic, examined the following assumptions of resilience theory: (a) resilience resources (i.e., types of personal resilience) and coping have specific functions in adaptating to adversity and (b) resilience processes (i.e., relationships between resilience resources and other variables) differ according to level of stress/adversity. From April-June 2020, 155 persons with cancer diagnoses and 150 without, matched on age, sex, and income, were recruited in the USA. A moderated-mediation model was used to test the theoretical assumptions: pandemic stress (independent variable), resilience resources (moderator variable), disengagement/denial coping (mediation variable), and quality of life (dependent variable), controlling for comorbid disease. Confirming theory, the Pandemic Stress X Resilience Resources moderator effect was significant for the no-cancer group [-.007 (-.013, -.001)], who reported less pandemic stress/adversity than the cancer group (M = 5.20 vs. M = 7.95; p <.05, respectively), but not for the cancer group. Also confirming theory, the Disengagement/Denial Coping X Resilience Resources moderator effect was significant for the cancer group [-.074 (-.132, -.015)], but not for the no-cancer group. Consistent with resilience theory, for the no-cancer group, the role of resilience resources was to decrease negative coping, thereby indirectly minimizing losses in quality of life. In contrast, in the cancer group, which reported higher levels of stress/adversity, the role of resilience resources was to reduce erosion of quality of life by reducing the impact of negative coping on quality-of-life. These results have clinical implications for both enhancing resilience resources and decreasing level of adversity in interventions for stress.