Here is illustrated the role of apostolic leaders and their place within councils of the Church. It is lived both in the unity of faith to which we jointly witness, and which together we confess and teach, and in the unity of hope and love which leads us to unite in fully committed fellowship. Unity needs a visible outward form which is able to encompass the element of inner differentiation and spiritual diversity as well as the element of historical change and development. This is the unity of a fellowship which covers all times and places and is summoned to witness and serve the world.' 27. Churches not outwardly united, for reasons of history or through deliberate separations, are obliged by their faith to work and to pray for the recovery of their visible unity and the deepening of their spiritual fellowship.
Communion is thus the fruit of redemption and necessarily an eschatological reality.
Christians can never tolerate disunity. They are obliged not merely to guard and maintain, but also to promote and nurture the highest possible realization of communion between and within the churches. Such a level of communion has a variety of interrelated aspects. It entails agreement in faith together with the common celebration of the sacraments, supported by a united ministry and forms of collegial and conciliar consultation in matters of faith, life and witness. These expressions of communion may need to be embodied in the law and regulations of the Church.