In his doctoral dissertation Sanctorum Communio, Bonhoeffer develops an interdisciplinary method to study the two-dimensionality of the religious community, whose manifestation in Christianity is the church as revelation and the empirical church in history. Previous research on this issue among Chinese scholars has presented Bonhoeffer's ecclesiology as a simple I-Thou-you structure. Unlike earlier studies, this article aims to represent the methodological complexity and farsightedness of Bonhoeffer's ecclesiology, in which he analyses the religious community with philosophical, sociological and theological conceptual tools. Moreover, this article traces the origins and development of Bonhoeffer's thought, highlighting both its similarities with and significant departures from the ecclesiology of the liberal theologian Reinhold Seeberg and the dialectical theologian Karl Barth. By comparing these three approaches to ecclesiology, the present article shows the originality and the creativity of Bonhoeffer's early thinking.