• Member Work Group Amnesty International, Munich, 1994
• Member Work Group Amnesty International, Leiden, 1995-1999
• Member of the Committee on Buddhism, preparing the new curriculum World Religions, University of Leiden, 1998-1999
• Chairman of the Department of the History of Christianity, Faculty of Theology and Religious Studies, University of Groningen, 1999-2011
• Member of the Curatorium of the Radboud Chair (for the study of Catholic Theology and Philosophy), Faculty of Theology and Religious Studies, University of Groningen, 2000-2004
• Member of the “Derde Weg” Committee, preparing a new theological curriculum, Faculty of Theology and Religious Studies, University of Groningen, 2001-2002
• Chairman of the Teaching Committee Religious Studies, Faculty of Theology and Religious Studies, University of Groningen, 2000-2006
• Member of the Steering Committee, Faculty of Theology and Religious Studies, University of Groningen, 2000-2001
• Member of the Committee on Public Relations, Faculty of Theology and Religious Studies, University of Groningen, 2000-2001
• Member of the Committee on the Working Load of Faculty Members, Faculty of Theology and Religious Studies, University of Groningen, 2000-2001
• Member of the Committee Bachelor/Master, restructuring the educational programmes of the Faculty of Theology and Religious Studies, University of Groningen, 2002
• Member of the Board of the Interuniversitary Institute of Missiology and Oecumenics, Utrecht, 2000-2003
• Chairman of the Department of Religious Studies and the History of Christianity, Faculty of Theology and Religious Studies, University of Groningen, 2001-2010
• Member of the Advisory Committee on Post-Doc Grants of the Dutch Organisation for Scientific Research (N.W.O.), 2001, 2002
• Member of the Advisory Committee on the Development of a Part-Time Curriculum Religious Studies, Faculty of Theology and Religious Studies, University of Groningen, 2002-2003
• Member of the Historical Society (Department of History, University of Groningen), 2003-
• Member of various Selection Committees of Ph.D. Students
• Chairman of the Teaching Committee Research Master, Faculty of Theology and Religious Studies, University of Groningen, 2006-2012
• Member of the Board of the Groningen Research School for the Study of the Humanities, 2003- 2010 (Spring 2005: Chair)
• Member of the Selection Committee of the Research Master, Faculty of Theology and Religious Studies, University of Groningen, 2004-2012
• Vice President of the Ernst Troeltsch Gesellschaft, 2005- (http://www.st.evtheol.uni-muenchen.de/troeltsch/etg/index.html)
• Chair/member of the Centre for Religious Studies, Groningen, 2006-2012
• Editorial Board Nederlands Theologisch Tijdschrift, 2007-
• Member/Chair Kerkhistorisch Gezelschap, 2006-2014
• Member of the Committee Mid-Term Review of the Research of the Department of Theology of Utrecht University, 2008
• Member of the Advisory Committee on Vidi Grants of the Dutch Organisation for Scientific Research (N.W.O.), 2009
• Member of the Board of the Institute for Integration and Social Efficacy (ISW), Groningen, 2009-2012
• Member of the Board of the National Research School for Theology and Religious Studies NOSTER, 2009-2012
• Member of the Advisory Committee on ‚Horizon Grants’ of the Dutch Organisation for Scientific Research (N.W.O.), 2011-2012
• Member of the Advisory Committee on the programme ‚Religion in Modern Society’ of the Dutch Organisation for Scientific Research (N.W.O.), 2012-2013
• Member of the Advisory Committee on Veni Grants of the Netherlands Organisation for Scientific Research (NWO), 2017
• Member of the Committee that prepares a ‚Zwaartegrant’ grant with the Netherlands Organisation for Scientific Research (NWO), 2018-2020
• Member of the Advisory Committee on Vici Grants of the Netherlands Organisation for Scientific Research (NWO), 2024-25