"Filling a lacuna in English language scholarship that might take scholars in the field by surprise, Bem directly and neatly explicates the development of Calvinist sects in the Reformed Church’s premier century in Poland-Lithuania. In doing so, he also suggests vital connections to the history of other contemporary confessions in the region and highlights important ties to the broader transnational history of Calvinism and the Reformation. [...] Bem’s work is a welcome addition to a field that has undergone significant rejuvenation in the past decade. It promises a wider impact as well: his research and his presentation are worthy of inspiring both popular interest and further scholarship on the topic.
Bryan Kozik, Davis & Elkins College, in Sixteenth Century Journal LV/1–2, pp. 329-331

“Kazimierz Bem’s fine monograph […] presents the fullest, clearest, and most comprehensive study of the Reformed faith in the Polish-Lithuanian Commonwealth available to an Anglophone audience today. […] For anyone serious about the world of Polish Calvinism, this book will be indispensable.”
Howard Louthan, University of Minnesota. In: Church History, Vol. 91, No. 3 (September 2022), pp. 674–675.


“important study […] This is the first book to provide a comprehensive assessment of Calvinism in Polish-Lithuania as a whole.”
Robert Frost, University of Aberdeen. In: Renaissance Quarterly, Vol. 75, No. 3 (Fall 2022), pp. 1065–1066.


“[...] The first modern historical synthesis in any language of Calvinism, broadly understood, in the entire Polish-Lithuanian Commonwealth. It can be recommended to all scholars and advanced students interested in the history of the Reformation in Europe.”
Wioletta Pawlikowska, Polish Academy of Sciences. In: Journal of Ecclesiastical History, Vol. 72, No. 4 (October 2021), pp. 881–883.


“This is the first scholarly monograph of the Reformed Churches in Poland-Lithuania in the period of the Reformation’s growth down through the beginning of its decline. [...] It is also a merit of the book to have drawn our attention to the manifold roles women played in Reformed congregations of the Commonwealth.”
Waldemar Kowalski, Jan Kochanowski University of Kielce. In: Religious Studies Review, Vol. 46, No. 4 (December 2020), pp. 551–552.