Read this book for Wolfhart Pannenberg, Alister McGrath, and Clark Pinnock's contributions.
Pannenberg argues for three things: 1) that the European nations' founding principles are nourished by cultural Christianity. 2) this founding principles include religious tolerance for pluralism, human rights, and church/state separation. They (public theology) are and should be distinguished from the ecclesial theology, which is a healthy distinction. 3) written at the dawn of the European integration movement, Pannenberg proposes the EU be based on a deepening ideological work of cultural Christianity, rather than the removal of it, for the sake of greater common good.