The Archdiocese of Chicago's Office for Ecumenical and Interreligious Affairs defines "the difference between ecumenical, interfaith, and interreligious relations", as follows:
Some interfaith dialogues have more recently adopted the name interbelief dialogue, while other proponents have proposed the term interpath dialogue, to avoid implicitly excluding atheists, agnostics, humanists, and others with no religious faith but with ethical or philosophical beliefs, as well as to be more accurate concerning many world religions that do not place the same emphasis on "faith" as do some Western religions. Similarly, pluralistic rationalist groups have hosted public reasoning dialogues to transcend all worldviews (whether religious, cultural or political), termed transbelief dialogue. To some, the term interreligious dialogue has the same meaning as interfaith dialogue. Neither are the same as nondenominational Christianity. The World Council of Churches distinguishes between 'interfaith' and 'interreligious'. To the WCC, interreligious refers to action between different Christian denominations. So, interfaith refers to interaction between different faith groups such as Muslim and Christian or Jew for example.
Throughout the world there are local, regional, national and international interfaith initiatives; many are formally or informally linked and constitute larger networks or federations. The often quoted "There will be no peace among the nations without peace among the religions. There will be no peace among the religions without dialogue among the religions" was formulated by Hans Küng, a Professor of Ecumenical Theology and President of the Global Ethic Foundation. Interfaith dialogue forms a major role in the study of religion and peacebuilding.
History records examples of interfaith initiatives throughout the ages, with varying levels of success in establishing one of three types of "dialogue" to engender, as recently described, either understanding, teamwork, or tolerance:
The historical effectiveness of interfaith dialogue is an issue of debate. Friar James L. Heft, in a lecture on "The Necessity of Inter-Faith Diplomacy," spoke about the conflicts among practitioners of the three Abrahamic religions (Judaism, Christianity and Islam). Noting that except for the Convivencia in the 14th and 15th centuries, believers in these religions have either kept their distance or have been in conflict, Heft maintains, "there has been very little genuine dialogue" between them. "The sad reality has been that most of the time Jews, Muslims and Christians have remained ignorant about each other, or worse, especially in the case of Christians and Muslims, attacked each other."