The recent nuclear crisis triggered by North Korea on October 9, 2006 and the subsequent changes of political environment of the Korean Peninsula and surrounding superpower countries demand the Korean Christians to think seriously about the impending future of the South-North relationship and the possibility of the reunification of two Koreas no matter what kind of process may be taking place during the course of reunification. Even the possibility of sudden collapse of the North Korean regime has been cautiously proposed. At least many politicians and observers agree to the reality that the Koreas are in the first stage of reunification after the historical South-North Summit Talks in 1990. What does Korean Christianity do for the impending reunification of the Koreas? Do we have a master plan for the future other than the old paradigm of nationalistic approach by the radical proponents of “Unification Theology” during the 1970s and 1980s? Do we have a mission plan for North Korean Christianity after the reunification other than the imperialistic church planting based on South Korean Christians' denominational lines? What if there is a sudden collapse of North Korea? The present author aims to provide a comprehensive outlook for the leaders of South Korean Christianity to review the possible scenarios of reunification process by examining the expecting results of reunification and/or collapse. The author predicts that there will be (1) massive migration of North Koreans to South Korea (2) minor territorial conflict with China (3) the rapid dismantle of North Korean society (4) the rapid rise of unemployment rate (5) the rise of anti-North Koreans sentiment (6) the dissatisfaction of North Koreans increases. To verify these predictions, the author investigates the preceeding case of reunification in Germany, the role of East German Church in the process of reunification and the following results, and the lesson that could be gathered from the cases of North Korean refugees who have tried to settle in South Korean society. As conclusion, the present author suggests to South Korean Church to prepare the followings: (1) the theological enterprises for the soft-landing of North Koreans' Ju-che Philosophy (2) the theological articulation for preventing social anomie among North Koreans (3) Making South Korean churches as a strong mediating structure to make a political space (4) Interpreting the Christian Gospel with the theology of peaceful reconciliation and mutual endurance (5) Becoming a member of reunification governance (6) Paradigm shift from “nationalistic strategy” to “global-dimension reunification plan”.