This article aims to examine the possibility and some challenges of doing public theology in Korea. While vibrant public theological discourse can be seen in many different contexts around the globe, the conservative Korean churches and theologians (which are the mainstream of Korean Christianity) remain largely indifferent to public theology. This is unfortunate, especially considering that the DNA of public theology can be seen throughout the history of Korean Christianity. As such, this article first examines how the early Korean church played a prophetic role and contributed to the wider society in the praxis of Christian faith that was socially engaged and publicly intelligible. This is then followed by a discussion on how the church was changed during the Cold War, the period of dictatorships, and the Industrialization era. It is especially important here to examine how a particular strand of Reformed theology from the United States, specifically that of J. Gresham Machen and Cornelius Van Til, was adopted. This had a profound influence on the reshaping of the role of the Korean church in public life. In conclusion, the article then urges the Korean church to engage in public theological discourse actively and extensively for the restoration of its prophetic role, its "bilingual" approach to faith praxis (navigating both contexts of the church and society), and to explore the rich diversity of the Reformed tradition, in order to recover its lost role as a public church.