David served as the principal-dean and professor of applied Christian ethics at Martin Luther University College (formerly Waterloo Lutheran Seminary) from May 1, 2005 to Aug. 31, 2015. After stepping down as principal-dean, he continues to serve as fellow in the school's Centre for Public Ethics.
David was the executive secretary for the denomination. For 25 years, he served as director of the Lutheran Office for Public Policy. He has served as chairperson of numerous ecumenical and multifaith organizations including the Canadian Council of Churches’ Commission on Justice and Peace and was a founding member and chairperson of the Interfaith Social Assistance Reform Coalition in Ontario.
He has represented the Evangelical Lutheran Church in Canada (ELCIC) on a wide range of ecumenical and multifaith coalitions that have addressed issues of economic globalization; social and health policy; Canadian foreign policy peace and disarmament; human rights and indigenous rights. He has represented the ELCIC on the governing council of the Lutheran World Federation and has been frequently a member of numerous election observer, human rights and ecumenical delegations.
As an ethicist, David’s expertise and research has focused on the contributions of Canadian ecumenical social justice movements in Canada; multifaith and ecumenical relations in public life, church-state relationships, corporate social responsibility, bioethical issues, and a range of human rights and public policy issues. Currently his research is focused in the area of public ethics.