This article is a reflection on Norman Doe's book Christian Law: contemporary principles (2013) from a Protestant and Continental perspective. Against the background of the self-evident impact of ecumenical progress in terms of church polity, it explores the relation between ecumenism and church polity from the opposite perspective: can the academic discipline of church polity foster ecumenism, as Doe suggests in his statement that ‘whilst doctrines divide, laws link Christians in common action’? After stating that a more nuanced understanding of the concept of ‘normativity’ is of fundamental importance in this respect, the article then indicates the possible risk of an ideological use of church law. Five reasons are given as to why church polity often hampers rather than fosters ecumenical progress, even if traditional doctrinal issues have been resolved. Finally, the fundamental category of divine law is explored, and its impact on ecumenical progress.