The purpose of this study is to examine the moderating effect of flow in the relationship between gratitude tendencies and psychological well-being of prayer participants. For this purpose, the following research questions were set. First, what is the relationship between gratitude disposition, psychological well-being, and flow of prayer participants? Second, what is the moderating effect of flow in the relationship between gratitude tendencies and psychological well-being of prayer participants? To solve the research problem, data from 304 prayer participants were analyzed using statistical methods. The results derived from the study are as follows. First, as a result of conducting a correlation analysis to examine the relationship between gratitude tendency, flow, and psychological well-being, it was found that there was a significant positive correlation between gratitude tendency and flow, gratitude tendency and psychological well-being, and flow and psychological well-being. Second, as a result of verifying the moderating effect of flow in the relationship between gratitude disposition and psychological well-being, it was confirmed that flow plays a significant role as a moderating variable in the relationship between gratitude disposition and psychological well-being. This study sought to confirm the moderating effect of flow in the relationship between gratitude disposition and psychological well-being with the purpose of improving the psychological well-being of prayer participants. It is significant that the discussion confirmed the influence of ‘flow’, an intervention point that can increase the psychological well-being of prayer participants. Additionally, it is significant in that it provided basic information about the psychological and emotional support that temples can provide along with prayers.