The Second Vatican Council’s Decree on Ecumenism 4 says that ecumenism is all “the initiatives and activities encouraged and organised according to various needs of the Church and as opportunities offer to promote church unity.” Our source of unity is “Jesus Christ … the same yesterday and today and forever” (Hebrews 13:8), Jesus in the power of the cross and the mystery of the resurrection, who unites us as one. All Christians, at least in some ways and despite their differences, experience this unity as they believe in the transforming power of the Word of God, share the waters of baptism, profess our faith through the Apostles’ or Nicene Creed, pray the Our Father, and share the courageous witness of many martyrs for the reign of God.
Fundamental to the Catholic understanding of the urgent need for Christian Unity is the prayer of Christ himself on the night before his suffering and sacrifice on the Cross: “May they be one as you, Father, are in me, and I am in you…may they all be one, that the world may believe it was you who sent me” (Jn 17:21). This prayer calls all Christians to reconciliation and unity at all times and in all places: not partial unity, or unity for some, or at different stage and in different ways, but the unity of all.
This unity is rooted in the community of the Father, Son and Spirit and is at the heart of creation itself. The unity of all humanity, not merely the unity of all Christians, is also therefore at the heart of Christ’s own mission. So the ecumenical movement achieves this unity of all things in Christ. It is not an optional vision, but integral to the coming of the reign of God. Pope John Paul II said it clearly in his Encyclical on Commitment to Ecumenism:
This unity, which the Lord has bestowed on his Church and in which he wishes to embrace all people, is not something added on, but stands at the very heart of Christ's mission. Nor is it some secondary attribute of the community of his disciples. Rather, it belongs to the very essence of this community (Ut Unum Sint 9).
The desire of all Christians to be united does not imply uniformity. Within the Christian community we need to celebrate the vast diversity that enhances the richness of the people of God. It is why we need to turn to our brothers and sisters in Christ from other churches so that we might journey with them by sharing our faith.
Much of the most exciting work of the Pontifical Council for Promoting Christian Unity, headed by Cardinal Walter Kasper, is encouraging this journey forward through “Receptive Ecumenism”. This implies not merely an ecumenism of friendship and common service and witness, but an exchange at the deepest level of what it is to be the Church. Thus we consider not “How can they be more like us?”, but “What we can receive from them with integrity, so that we can grow together and rediscover our unity?” Thus we can receive from each other not just our traditions, our culture and customs, including mutual understanding of our theological thinking and our different ways of putting and doing things. We also receive from each other in an “ecumenism of life” enabling a concerted life as the one Church in witness and service to the world. A good example of this in action is IARCCUM, the International Anglican Roman Catholic Commission on Unity and Mission, which will serve to translate ecumenical dialogue into action and practical reality.
Receptive Ecumenism and ecumenism of life are also intended to overcome the impasse in the road to Christian Unity noted by Pope John Paul. He recognised that we had all become settled in a spirituality of unity, which was warm but static: it had lost its drive towards visible and organic reconciliation. He therefore called for the cultivation of a “spirituality of communion”, a desire to achieve the re-integration of the Church in full communion and the realisation of the fullness of the gift of the Eucharist. In Ut Unum Sint, his great Encyclical affirming the Catholic Church’s commitment to ecumenism. he asked leaders of other Churches to say how the office of Pope, for instance, could be developed so to be of service to Christians of other Christian traditions and communities, in order that they could receive something of what the Petrine ministry offers to Catholics and their sense of unity. In this process Catholics by the same token Catholics could learn valuable insights from other Christians and take what in their churches can might enrich the Catholic Church. The responses have been detailed and generous. They are currently being gathered and considered. They could well take Christianity into a new period of ecumenical progress together.