From ancient times in Korea, rituals to the ‘Han-ul-nim,’ ‘Ha-neu-nim,’ ‘Han-im’ or the ‘Heavenly God’ by the nation and rituals to the Heaven by the people were handed down. A ritual to the Heaven was one of the most important rituals among the national rituals. It had great historical meanings as a political ritual as well as a religious symbol. Also, it had been considered as a significant ritual through which Korean people had kept up autonomous independence and historical identity. The ritual services to the Heaven, that was kept up from ancient times to the Goryeo Dynasty, were discontinued nationally during the Joseon Dynasty almost for five hundred years. In such a situation, on the contrary, the characteristics of ritual services to the Heaven by the people were strengthened that were held secretly by the common people. Particularly, there were the Seon ceremony of Daejong-gyo (faith), the Go-cheon-je (declaration service to the Heaven) of Bocheon-gyo, which was in lineage from Jeungsan-gyo, the prayers at the mountains for the dharma authentication of Won-Buddhism and so on in relation with ritual services to the Heaven by the people in new religions of Korea. They became a driving force to recover autonomous independence and historical identity of Korean people from Japan in the Donghak (Eastern Learning) movement, March First Independence Movement, and the independence movement by Daejong-gyo. First, this paper introduced briefly the ritual services to the Heaven by people in new religions. Second, it elucidated that the ‘prayers for the dharma authentication’, which is the main theme of this paper, were hidden ritual services to the Heaven which were not revealed to people and had meaning of sacrifice rituals. Third, it interpreted the symbolic meaning and structure the ‘flag of Eight Trigrams for divination (palgoae)’, which was used during the prayers for the dharma authentication, from the perspective of the science of change (yi). Afterward, the ‘diagram of Irwon and Eight Trigrams’ became base to form the doctrinal system such as the truth, faith, and practice of Irwon-sang (One Circle Symbol). Even presently, it demonstrates that the Won-Buddhist Order seeks the universal unity that corresponds to the heaven, earth, and eight directions, standing for one unit by ten persons.