The purpose of this study is to explain the relationship between Protestantism and the state in South Korea, focusing on major events since the Liberation. This is because during the period of preventing the spread of COVID-19, it was necessary to look at changes in the relationship between the state and religion in South Korea through the actions of Protestants and Protestant churches, including Shincheonji and Sarang First Church members. The content of this study is to point out the parts that can and cannot explain the Korean situation through religion and state relations theory. This is because persuasive theories explaining religion and state, religion and politics, and religion and government relations cannot be explained in South Korean religion and state relations. After that, this explained the relationship between Protestantism and the state from the Liberation to the present with examples of cooperation and conflict. The conclusion of this study is that the state has recently intervened in many social areas as well as religion. Conflicts and cooperation occur when the role of the state increases and the function of religion expands. At this time, Protestantism unconditionally confronts the “freedom of religion” frame. When the legitimacy of the state was weak, the state tried to incorporate a group of religious leaders into its governance structure. Protestant leaders in Korea worked together to achieve personal enlightenment or pursuit of interests, to survive or expand religious organizations, and to maximize their social status or influence. International relations such as colonial motherland and neighboring powers are also important as variables that affect the relationship between the state and religion. In Korea, Protestantism should be viewed at the same level as the Korea-U.S. alliance and the anti-communist alliance, not just religion.