To the Reverend Dr Philip Potter
General Secretary World Council of Churches
The ecumenical importance of the celebration by the World Council of Churches of its Fifth Assembly at Nairobi moves us to address you with words of friendship, encouragement and Christian greetings. Because your desire for unity and reconciliation coincides with our own, we have been happy to appoint sixteen Catholic observers who are with you on this occasion. And to give further evidence of the confidence which it awakens in us are asking our brother Cardinal John Willebrands to tell you at greater length of our interest in the Assembly and of our interest in the Assembly and of our warm good wishes for its successful outcome.
We hope that the Assembly will indeed have an important influence on the life of the World Council of Churches, on its member Churches and on all who are committed to the ecumenical movement. We trust that the efforts which the Catholic Church has made and will continue to make to promote the ecumenical movement and, wherever possible, to collaborate with the World Council of Churches will continue and grow even greater with God's help. May the assurance of our fraternal solidarity hearten you for the years ahead.
Be assured that our thoughts and fervent prayers are with you in these days. May God grant you courage and faithfulness and joy in doing his will, and the strength to move steadily forward, through the assistance of the Holy Spirit, towards the fulfilment of Christ's prayers to the Father: « . . . that they may be one, even as we are one» (Io. 17, 11).
From the Vatican, 20 November 1975.