Background. Religious and spiritual (R/S) struggles may impact mental health treatment and recovery processes. The current study investigates how R/S struggles play a role in mental illness and what approaches are experienced as helpful. Methods. Thirty-five semi-structured interviews with clinical mental health patients in a Christian (N = 15) and a secular (N = 20) mental health clinic were narratively analyzed. Results. R/S struggles are common in people who suffer from mental illness and often coexist together with R/S support, mostly fluctuating over time. In summary, patients experience R/S struggles as negative feelings (e.g., loneliness, shame, mistrust) and the absence of positive feelings (e.g., hope and peace). These are influenced by someone’s R/S background and beliefs, as well as by the illness and other events. All participants appreciated a receptive approach (1) and many preferred an active approach (2) by mental health professionals. Some patients reported benefits from a directive approach (3). Conclusions. R/S struggles are tightly connected with other aspects that play a role in patients with mental illness. Mental health professionals are recommended to listen to patients’ narratives and carefully consider whether or not further interventions, in order to enhance R/S support and reduce R/S struggles, might be appropriate.