The purpose of this study is to examine the effect of religious orientation on depression, one of the negative variables in humans. Intrinsic religious inclinations, which are distinguished by the motives and attitudes that individuals have toward religion, are set as independent variables. In addition, this study examined the path to depression by setting mentalization as a mediator as a psychological protective factor. To this end, 400 adult men and women in their 20s and 50s in 16 cities participated in the study. Descriptive statistical methods were used to examine the demographic characteristics of the study subjects, correlation analysis was conducted to verify the relationship between religious orientation, depression, and mentalization, and structural equation modeling was conducted to investigate the mediation of mentalization. The path coefficient was calculated by verification. The results of the study are as follows: First, extrinsic religious orientation does not directly affect depression. Second, intrinsic religious orientation had a negative effect on depression. In other words, intrinsic religious orientation, which is a mature religious orientation, plays a role in reducing depression. Third, it was found that the intrinsic religious tendency did not go through mentalization and did not mediate it by directly negatively correlating to depression. This study is the first study to verify the mediating effect of religious status and mentalization, and it is meaningful to set out independent variables such as external religious tendency and intrinsic religious tendency to broadly grasp the religious tendency in psychological counseling.