This study tries to illustrate that oral history can open a new prospect in the field of a Korean church history, a modern history of Korea, and World history. Firstly, this paper deals with theoretical approach about oral history. A basic direction of oral history is to supplement establishing materials and to make people’s memories be historical. Furthermore, oral history aims at new historical fields through enlargement of interviewees and reflection on philosophy of history and historical theory. General historians overlook a religious inner side easily. However that is a mistake of ‘process-reduction.’ Oral history is an alternative overcoming that kind of mistake. Especially oral history of religion is a historical method to discover new histories by their own confess-language differed from the fact-language and the interpret-language. Secondly, this paper suggests that the oral history of religion probes many varieties of historical layer, focusing on the Christians who were participated in the Korean pro-democracy. Christian democratizers played a leading role under the military dictatorial government. Moreover, they consolidated not only people in many fields such as religion, press, student, judicial officer circles and so on nationally, but also compatriots overseas. Outside of those, this paper prefigures a possibility of enlargement of oral history by illustrating examples of various historical layers. Finally, the present writer finishes, giving discourse assignments to the readers. One is to reflect the way of sharing memory. If the survivors passed away, their experiences become extinct. In order to overcome that crisis, a oral history needs to be investigated, searched for the way of sharing memory. Another is to reflect on a position of a oral history between micro-history and macro-history. A oral history is located in the context of micro-history. Nevertheless, it is important to work a oral history having a mind to criticize individuality and generality in micro and macro dimension.