This office works in the local church to fulfill the pledge of the Catholic Church at Vatican II (Decree Unitatis Redintegratio) "to work for Christian unity," a unity that by its nature "requires full visible communion of all Christians." The 1993 Directory for the Application of Principles and Norms on Ecumenism (Pontifical Council for Promoting Christian Unity) and Pope John Paul II's 1995 encyclical Ut Unum Sint guide these activities and initiatives.

The office also seeks to develop relationships and initiatives with non-Christian religions according to the Vatican II Decree Nostra Aetate.