This article analyses how Finnish hegemonic nationalism was contested by peace movements in Finland from 1919 to 1932. First and foremost, Finnish peace movements contested hegemonic Lutheran‐patriotic discourses, which they perceived to have been maintained especially by the Lutheran Church of Finland. Thus, hegemonic Lutheran‐patriotic discourses were contested by peace movements through three church‐related discursive contexts: (1) biblical‐doctrinal interpretations, (2) Christian revivalism and (3) churches' peace ecumenism. Results of this article imply that contesting happened especially through religious discourses, which considered a nationalist state church idolatrous. Peace activists depicted themselves as true Christians and patriots, arguing that peace ecumenical cooperation with them and other churches enabled state churches to renounce hegemonic nationalism. Based on these results, I suggest that when hegemonic nationalism is intertwined strongly with Christianity and the state church, nationalism is challenged through questioning its alleged Christian basis.