The Swiss theologian Hans Küng writes in his The Church: "The road to unity is not the return of one church to another, or the exodus of one church to join another... (the Christian) unity is not the subjection of one church to another, but the mutual regeneration and mutual acceptance of community through mutual giving and receiving."1 The promotion of the restoration of unity among all Christians is one of the chief concerns of the Second Vatican Council (UR l). This is affirmed in the decree Orientalium Ecclesiarum, which says that the Eastern Churches in communion with the Apostolic See have a unique role to play in promoting the unity of all Christians, particularly Easterners (OE 24).The one Catholic Church consists of one Latin Church and 23 Eastern catholic sui iuris churches. The presence of Catholic Eastern churches in communion with the Roman Church makes us aware that the Catholic Church is much more than the Roman Catholic Church. John Madey says: "The Oriental Catholic Churches are making the Universal Church more Catholic than the Roman Catholic Church would be able to do. They are not Roman, but in communion with the Roman Church, as the Apostles were not Peter, but in communion with Peter."2 Moreover, the 'communion of Churches' implies that the different individual Churches share their heritages and value each other with openness and learn from each other and move towards convergence.The Second Vatican Council encourages the Eastern Catholic churches in their particular task of fostering the unity of all Christians, especially of Eastern Christians (Cf. OE, 6, 24). They always try to recover the sources and the highest fidelity to ancient traditions. The very existence of Catholic Eastern Churches has an ecumenical dimension. However, to find themselves in this realm of responding to these issues, they need a stronger sense of their own identity; they need to establish their contact with their own most in-depth resources. The emergence of the theology of the Individual church3 and communion ecclesiology paved the way for restoring their lost identity and most comprehensive resources and thereby progressing in ecumenism.