‘Religious Nationalism’ is ‘Korean Religious Community’ in a strict sense. It does not originate from past nor was it modified rationally. Thus if ‘Religious Nationalism is thought to be a ‘product’ of people feeling that they somehow ‘belong’ to one community it will lead to and error of simplification of Nationalism. Moreover in modern history of Korea, the Nationalism had influence over religion, and thus came the ‘Religious Nationalism’. Due to this fact, the debate about ‘Religious Nationalism’ should be similar to a debate about existence where it is devided into realism and nominalism. In this context this study aims to review the Korean New Religion’s idea of ideal world by implementing ‘Religious Nationalism’. In terms of modern history Korea has more rough spots than European countries who lead the modernism. Based on this rough modern history, every Korean New Religions possesses it’s own unique idea about ideal world despite the difference in the methods and routes. Korean New Religions take active measures aiming to encourage people, and this can be seen as a reflection of New Religion trying to answer people’s wishes and desires. Jeung San, whom is reviewed in this paper, also advocated Cheonjigonsa (天地公事; Reordering of the Universe) to people by utilizing a reorganized religious act of Jeung San, which is based on self-awakening. Jeung San approached people with familiar form of religion by acculturating Maitreya faith’s classical idea of ideal world, and developed Jeung San’s own religious ideal world Hoocheon(後天; later world). The ideal world created by Jeung San saw Won(冤;grievance) as the cause for social tension and disorder, and by relieving Po-won(抱冤; mutual conflict and nourishing grievances) with Hae-Won(解冤; resolution of grievance) Jeung San tried to restore the nature of human beings. Moreover Jeung San tries to materialize the ideal world by not just using religion reasons, but by actually taking religion actions. For example, by suggesting a practical and direct action of Cheonjigonsa, Jeung San not only created ideation of ideal-world, but also tried to transform the real world into an ideal world. This idea of ideal-world empowered people with ethnicawareness and self-reliance with the belief of becoming proud citizen of a nation which will lead the world after Hoocheon-Gaebyeok (後天開闢; great opening era of the later world) As a result it acted as the backbone of resistance against Japanese colonization and was able to create ‘Religious Nationalism’.