[Objective] In this paper, I diagnose the de-religionization that characterizes as a result of the loss of religiosity. I will present the concepts of religiosity and spirituality in Buddhism from the perspective of early Buddhism and propose a specific methodology for Buddhist spirituality education. [Contents] I defined Buddhist religiosity by analyzing the Buddha's preaching declaration(傳道宣言) and the concept of kusala. Among them, the social dimension is proposed as the concept of Buddhist religiosity, and the personal dimension is proposed as the concept of spirituality. Through this, I argued that the origin of Buddhist religiosity lies in the Proclamation. And I found the specific meaning of 'Buddhist spirituality' in the concept of kusala, and revealed that 'eightfold path' is suitable as a specific method of Buddhist spiritual education. [Conclusions] Buddhist religiosity is related to the identity of Buddhism pursued by the Buddha, and it is the 'socialization of enlightenment' shown in the 'Proclamation'. Spirituality, as a life-changing principle, is the process of enlightenment: religiosity manifests as a function of socialization and healing, while spirituality manifests as inner wholeness.