If the Christian Church prioritizes its existence and expansion, it will turn to the entity that approves of it and protects it. When the Modern Japanese emperor’s state approached the church as his grace, the Japanese Christian Church showed its gratitude and pledged its allegiance to the emperor. In the Sino-Japanese War, which assisted modern Japan in becoming an imperial-ist country, the Japanese Christian community was in favor of a war under the pretext of a “righteous war” to maintain a lasting peace in the East. However, during the Russo-Japanese War, when most of the Christians were actively in favor of the war, there were a few anti-war voices among small groups of Christians that had not been heard during the Sino-Japanese War. There was a tension that could not be easily resolved in the Japanese Christian Church. In particular, Gokyō, a Christian journal published by the Japanese Methodist Church, one of the major Protestant denominations, simultaneously presented two interesting and conflicting stances regarding the Russo-Japanese War (just war vs. anti-war). In this paper, we examine the diverging perspectives presented in Gokyō and explore various patterns of religion–war relations. Through this, we can see an example of two opposing arguments of just war and anti-war that coexisted and competed on the grounds of Christianity.