In this study, we combined the Job Demands-Resources model and Conservation of Resources theory with work-family enrichment (WFE) literature, using the Resource–Gain–Development perspective in particular, in order to (1) investigate the motivating and wellness-promoting role of job and home resources in predicting enrichment in work and family leading to further positive outcomes, and (2) examine positive gain spirals between the study variables over time. More specifically, we investigated whether job resources predict work engagement through WFE, and similarly, whether home resources predict marital satisfaction through FWE. We also investigated the reciprocal effects between job and home resources, enrichment in both directions, and well-being in both domains. The study was based on a two-wave, 3-year, full panel design among Finnish dentists (N= 1,632). Results showed that job resources at T1 predicted WFE at T2, and WFE and engagement reciprocally influenced each other over time. Home resources at T1, on the other hand, did not predict family-work enrichment (FEW) at T2; instead, FWE at T1 influenced both home resources and marital satisfaction at T2. Moreover, we found reciprocal impacts (‘gain spirals’) between domain-specific resources (job/home resources) and domain-specific well-being (engagement/marital satisfaction) and between WFE and engagement, thus supporting the Conservation of Resources theory. The same results were found for both genders, suggesting that similar enrichment processes may take place among both women and men. Theoretically, this study suggests that adding the idea of positive feedback loops might benefit the models theorizing WFE.