For religious heritage tourism, the key to a destination’s reputation lies in enabling visitors to fully experience the sacredness or a unique spiritual experience offered by the site. The authenticity of the tourism experience and perception is the most significant factor influencing visitors’ perception of the sacredness of religious or holy sites. However, there is currently a lack of sufficient references and evidence to explore the relationship between tourists’ authentic experiences and their perception of sacredness in religious heritage tourism. The aim of this study is to elucidate the causal relationship between the characteristics or attributes of tourists’ authentic experiences and their perception of the sacredness of the destination. Furthermore, it seeks to explore resource development and site creation strategies for religious tourism destinations to continuously enhance the sense of sacredness of these places. The Shamanic cultural traditions in the traditional settlements of Northeast China provide a subtly different context for this study. However, the topics discussed have broad applicability in constructing the network of relationships between the characteristics of tourists’ experiences and their perception of sacredness in religious heritage tourism. This study applied the causal decision analysis model based on data mining (RSA-DEMATEL) and established a causal network diagram between core attributes based on clarifying the behavioral rule knowledge (i.e., If…Then… rules) between tourists’ travel experience (conditional attributes) and the perception of place sacredness (decision-making attributes). The study finds that enhancing tourists’ perception of the sacredness of a destination is related to authentic tourism experiences, the ability to observe believers and participate in the religious activities of local residents, landscapes that reflect local traditions and historical culture, as well as the number of tourists and the extent of commercial activities. This research offers further insights into the sustainable development of religious tourism, providing a critical conceptual framework and data analysis model for subsequent related studies, contributing significantly to both theory and practice.