Religious education became a part of the regular school curriculum as elective courses upon enforcement of the Fourth Curriculum (Ministry of Education announcement no.442, Dec. 31, 1981). Since then, through the implementations of the 5th, 6th and 7th Curriculum and the 2015 Revised Curriculum, religious education was progressed by the ministry where its two incomplete forms, the religious and cultural education of ‘general religious knowledge’ and an education based on ‘faith’ by each religious order and denomination, coexist. The difficulty in establishing one unified purpose of religious education is also obscuring the attributes of religious education itself. In the paper, this author analyzed the causes of this obscurity and asserted that, in religious education, the teachings should embrace this religiously plural society and not emphasize on the ‘knowledge’ and ‘faith’ separately but the together. Having established that, the incorporation of the ‘reflective religious education’ curriculum in pace with our multi-cultural and religious society in the 2015 Revised Curriculum is encouraging; but the obscurity of the purpose of the education is still a task to be solved. This paper is composed as follows : 1. The history of the changing purposes of religious education was generally explored, 2. The 2015 Revised Curriculum critically considered the purpose of religious education, and 3. Conventional purposes of religious education were analyzed in two standpoints, value neutrality and religiosity. First, the pursuit of the ‘general’ ‘value neutral’ religious knowledge is prone to the error of normative generalization with respect to the world of religious abyss. On the other hand, the religious education based on the missional aspiration led by schools founded by religious organizations, in the standpoint of the assurance of their identity, is now facing the need to learn about other religions. At present, these schools tend to avoid education on general religion due to potential confusion in ‘religious identity’, but it was revealed that ‘religious identity’ could be formed through the mirrors of other religions. Third, interreligious education was proposed as an alternative in addition to practice of dialogic religious education to overcome the obscurity in the purpose of religious education.