在一貫道，上帝是人格神，理天是神聖空間，人必須超氣入理，脫離氣天、象天回歸理天，才能超生了死。王覺一對宇宙本體的理解乃是綜合了《尚書》與《易傳》之義。根據《尚書》指出「上帝」之義；根據《易傳》指出「理天」之義。而作為「範圍天地之神」的「上帝」即是「至靜不動」的「理天」。王覺一對宋明理學的繼承在於：接受了朱熹、羅欽順的理氣二分思想，與王陽明的心性為一思想，並將理氣二分思想，轉化為理、氣、象三分的宇宙架構。因為氣天、象天中的一切事物皆分享了理天的實在性，所以理、氣、象三天具有客觀實在義。但王覺一闡釋理、氣、象三天，主旨是要引導人修行以求返本還源、回歸理天。因此其主旨乃在強調：人若能從氣天、象天中覺知「天理」、實踐「天理」，則原本視為氣天、象天的環境也可以在當下立即轉變為理天，這可視為理、氣、象三天的主觀境界義。依王覺一，理天才是宇宙的實相，人是否能看見此實相，關鍵在於：是否能覺知天理、實踐天理，亦即是否能「通天下之故」、「返本還源」。 In the I-Kuan Tao, God has the personality traits. The "Lii Tian" is the sacred space that people should get ride of the "Chi Tian" and "Zhuyin Tian"and then to be able to make themselves back to the "Lii Tian" which could be out of life and death. Wang Jueyi's understanding of the ontology of the universe combines the meanings of "ancient chinese book" and "Yi Zhuan". The meaning of "God" was by "ancient chinese book" and the meaning of "Lii Tian" was from "Book of Changes. The God is "Lii Tian" which is sedentary. Wang Jueyi' s Confuclanism of Song Dynasty and Ming Dynasty succeed to Zhu Xi and Luo Qin-shun's dichotomy that "Lii" and "Chi" was separated into two parts and also included thinking of Wang Yangming's which is one of mind and personality. Wang Jueyi converted "Lii" and "Chi" to the universe infrastructure that included three parts "Lii", "Chi" and "Zhuyin". Since "Chi Tian" and "Zhuyin Tian" shared the reality of "Lii Tian". Base on this, "Lii Tian", "Chi Tian" and "Zhuyin Tian" are existence with objec-tive.However, Wang Jueyi explained the reason, "Lii Tian", "Chi Tian" and "Zhuyin Tian" that the essence is to guide people to prac-tice in order toreturn the source and return to Li Tian. Therefore, its essence is to emphasize that if people can perceive and put into practice "the natural principle" from "Chi Tian" and "Zhuyin Tian" which also can be immediately transformed into "Lii Tian". For thisreason that could be regards as the "Lii Tian", "Chi Tian" and "Zhuyin Tian" are reasonable with subjective.According to Wang Jueyi, "Lii Tian" is the reality of the universe. Whether people can understand this reality depends on whether they can perceiveand practice the natural principle, that is, whether they can "understand the origin of the world" and "return to his primary source".
