This study aims to investigate the historical background of the anticommunistic position of the Korean Church. Now anticommunism is no more considered to be as a taboo in the Korean society. The Korean Church, however, is regarded as the most vehement anticommunist group among the institutions of the Korean society, and this will be an obstacles for the integration of society as well as for the future of reunification of Korea. By 1920s, there were no conflicts between the socialists and the church leaders in Korea, because they had a common goal, namely liberation from the Japanese colonialism. In the 1930s, the Korean Church had an inclination to keep individualistic and mystical faith, and the socialists began to criticize her and persecuted Christians living in the district of Manchuria in China. This made a gap between the socialists and the Christians. The Korean war left the psychological scar to the Christians and strengthened the anticommunistic position of churches. To the Christians, the communists were regarded as the Satan or Anti-Christ to fight against, not to be reconciled with. The anticommunism played a core role not only in the split of the Korean society, but also in the Korean Church. In the 1950s and 1960s, the theological fundamentalists condemned the liberalists or moderatists as anticommunists and justified their separatistic attitude. Today, this anticommunistic position of the Korean Church are expressing more openly in a way of a mass demonstration with the so-called prayer times for the nation. However, the gospel that Christians should love the enemy challenges the anticommunistic position of the Korean Church to reflect their ideological position to cope with the coming post-ideological age and the new tasks of the reunification of nation.