Objectives: High tension is the leading cause of the increased risk of mortality among family caregivers (FCGs), resulting in inadequate care and abandonment of the patient. Spirituality promotion is a sense of mastery and control and strength to endure the stressors of illness. To the best of our knowledge, no tool is available for investigating the current spiritual state of the FCG and identifying the need for spiritual intervention in Iran. Therefore, the present study aimed to identify the level of independence of patients with chronic disease and to explore the concept of spirituality and psychometric of related scale, namely, caregiver's spiritual empowering scale (CSES). Materials and Methods: This study used a multiphase mixed-method approach and was conducted from June 2016 to August 2018 in the southwestern region of Iran. The cross-sectional surveys of activities of daily living (ADL) and instrumental activities of daily living (IADL) were conducted on people with chronic diseases (n = 389) in the first phase. In the second phase, the exploratory sequential mixed method was applied for content analysis study (n = 26) and psychometric of CSES in FCG (n = 395). Results: The caregivers' age was within the range of 17-74 years (42 Mean +/- 12SD). Based on the results of ADL IADL, 87% and 99.5% of patients were dependent or in need of help. In the qualitative study phase, four main categories emerged in the context of "Empowering spirituality". The reliability and validity of CSES including 12 items loaded one a single factor were confirmed based on the content validity ratio >0.45, content validity index >0.78, kappa coefficient >0.75, impact score >1.5, alpha = 0.92, interclass correlation coefficient = 0.91, 95% CI = 0.90-0.92, r = 0.57, P = 0.000, standard error of the mean = 1.64, and Kaiser-Meyer-Olkin index = 94, P < 0.001. Conclusions: In general, spiritual empowerment is essential as a low-cost and effective method in increasing the dependence of people with chronic diseases and the risk of burnout in FCG. Accordingly, the CSES is considered a valid and reliable instrument for measuring the status of empowerment spirituality in informal caregivers and the effectiveness of interventions.