This article is a revised version of the author’s publication in the ‘Review of Ecumenical Studies. The Journal of Lucian Blaga University of Sibiu’, Rumania. Permission for publication is granted by the author, Prof. Dr Leo Koffeman. The author is Professor Extraordinarius, in the Department of Church History and Church Polity, at the Faculty of Theology, University of Pretoria, South Africa. ; With a view to the theme of church renewal, this article explores the role of a well-known and popular phrase in the Reformed tradition within Protestantism, that is, ecclesia reformata semper reformanda [‘the reformed church should always be reformed’]. Is this a helpful slogan when considering the possibilities and the limitations of church renewal? Firstly, the historical background of this phrase is described: it is rooted in the Dutch Reformed tradition, and only in the 20th century it was widely recognised in Reformed circles. Against this background the hermeneutical problem, linked with the principle of sola Scriptura, is presented, and put into an ecumenical ecclesiological perspective: the church is grounded in the gospel. Finally, the article focuses on church polity as an important field of renewal, taking into account Karl Barth’s interpretation of this phrase. From this perspective, a balanced and ecumenical approach of church renewal is possible. ; http://www.hts.org.za ; am2015