Religion has been largely absent in diplomacy, particularly in the Western world, for a long time. Some would even say since the Enlightenment. Moreover, religion has been ignored in present-day theories of international relations, and thus also in diplomatic studies. A recent 'resurgence' of religion in international affairs, however, presents an opportunity to apply moral insights and religious concepts towards the development of peaceful settlements of conflicts through diplomatic techniques. The approach of faith-based diplomatic approaches may infuse those insights into today's political reality, thereby incorporating important initiatives, such as reconciliation and forgiveness, into conflict resolution.This article examines the concept of faith-based diplomacy as declared track-two diplomacy in the context of classical track-one diplomacy. It starts with a brief overview of political science research of track-one and track-two diplomacy. Additional focus is applied to the principles and practices of Christian faith traditions and their potential contributions to peace-building. Finally, the article also evaluates the 'spiritual roots' of diplomacy. It assesses how 'diplomatic theory and practice can be informed and enriched by experimenting with spirituality'. The success of faith-based diplomacy lies in its insights and applications of religious values and methods. But it is also its realistic approach that makes faith-based diplomacy a promising, needed and additional style of diplomacy even though it cannot be properly located within either track-one or track-two diplomacy.