INTRODUCTION

1. Ut unum sint! The call for Christian unity made by the Second Vatican Ecumenical Council with such impassioned commitment is finding an ever greater echo in the hearts of believers, especially as the Year 2000 approaches, a year which Christians will celebrate as a sacred Jubilee, the commemoration of the Incarnation of the Son of God, who became man in order to save humanity.

The courageous witness of so many martyrs of our century, including members of Churches and Ecclesial Communities not in full communion with the Catholic Church, gives new vigour to the Council's call and reminds us of our duty to listen to and put into practice its exhortation. These brothers and sisters of ours, united in the selfless offering of their lives for the Kingdom of God, are the most powerful proof that every factor of division can be transcended and overcome in the total gift of self for the sake of the Gospel.

Christ calls all his disciples to unity. My earnest desire is to renew this call today, to propose it once more with determination, repeating what I said at the Roman Colosseum on Good Friday 1994, at the end of the meditation on the Via Crucis prepared by my Venerable Brother Bartholomew, the Ecumenical Patriarch of Constantinople. There I stated that believers in Christ, united in following in the footsteps of the martyrs, cannot remain divided. If they wish truly and effectively to oppose the world's tendency to reduce to powerlessness the Mystery of Redemption, they must profess together the same truth about the Cross.¹ The Cross! An anti-Christian outlook seeks to minimize the Cross, to empty it of its meaning, and to deny that in it man has the source of his new life. It claims that the Cross is unable to provide either vision or hope. Man, it says, is nothing but an earthly being, who must live as if God did not exist.

2. No one is unaware of the challenge which all this poses to believers. They cannot fail to meet this challenge. Indeed, how could they refuse to do everything possible, with God's help, to break down the walls of division and distrust, to overcome obstacles and prejudices which thwart the proclamation of the Gospel of salvation in the Cross of Jesus, the one Redeemer of man, of every individual?

I thank the Lord that he has led us to make progress along the path of unity and communion between Christians, a path difficult but so full of joy. Interconfessional dialogues at the theological level have produced positive and tangible results: this encourages us to move forward.

Nevertheless, besides the doctrinal differences needing to be resolved, Christians cannot underestimate the burden of long-standing misgivings inherited from the past, and of mutual misunderstandings and prejudices. Complacency, indifference and insufficient knowledge of one another often make this situation worse. Consequently, the commitment to ecumenism must be based upon the conversion of hearts and upon prayer, which will also lead to the necessary purification of past memories. With the grace of the Holy Spirit, the Lord's disciples, inspired by love, by the power of the truth and by a sincere desire for mutual forgiveness and reconciliation, are called to re-examine together their painful past and the hurt which that past regrettably continues to provoke even today. All together, they are invited by the ever fresh power of the Gospel to acknowledge with sincere and total objectivity the mistakes made and the contingent factors at work at the origins of their deplorable divisions. What is needed is a calm, clear-sighted and truthful vision of things, a vision enlivened by divine mercy and capable of freeing people's minds and of inspiring in everyone a renewed willingness, precisely with a view to proclaiming the Gospel to the men and women of every people and nation.

3. At the Second Vatican Council, the Catholic Church committed herself irrevocably to following the path of the ecumenical venture, thus heeding the Spirit of the Lord, who teaches people to interpret carefully the "signs of the times" . The experiences of these years have made the Church even more profoundly aware of her identity and her mission in history. The Catholic Church acknowledges and confesses the weaknesses of her members, conscious that their sins are so many betrayals of and obstacles to the accomplishment of the Saviour's plan. Because she feels herself constantly called to be renewed in the spirit of the Gospel, she does not cease to do penance. At the same time, she acknowledges and exalts still more the power of the Lord, who fills her with the gift of holiness, leads her forward, and conforms her to his Passion and Resurrection.

Taught by the events of her history, the Church is committed to freeing herself from every purely human support, in order to live in depth the Gospel law of the Beatitudes. Conscious that the truth does not impose itself except "by virtue of its own truth, as it makes its entrance into the mind at once quietly and with power",² she seeks nothing for herself but the freedom to proclaim the Gospel. Indeed, her authority is exercised in the service of truth and charity.

I myself intend to promote every suitable initiative aimed at making the witness of the entire Catholic community understood in its full purity and consistency, especially considering the engagement which awaits the Church at the threshold of the new Millennium. That will be an exceptional occasion, in view of which she asks the Lord to increase the unity of all Christians until they reach full communion.³ The present Encyclical Letter is meant as a contribution to this most noble goal. Essentially pastoral in character, it seeks to encourage the efforts of all who work for the cause of unity.

4. This is a specific duty of the Bishop of Rome as the Successor of the Apostle Peter. I carry out this duty with the profound conviction that I am obeying the Lord, and with a clear sense of my own human frailty. Indeed, if Christ himself gave Peter this special mission in the Church and exhorted him to strengthen his brethren, he also made clear to him his human weakness and his special need of conversion: "And when you have turned again, strengthen your brethren" (Lk 22:32). It is precisely in Peter's human weakness that it becomes fully clear that the Pope, in order to carry out this special ministry in the Church, depends totally on the Lord's grace and prayer: "I have prayed for you that your faith may not fail" (Lk 22:32). The conversion of Peter and that of his Successors is upheld by the very prayer of the Redeemer, and the Church constantly makes this petition her own. In our ecumenical age, marked by the Second Vatican Council, the mission of the Bishop of Rome is particularly directed to recalling the need for full communion among Christ's disciples.

The Bishop of Rome himself must fervently make his own Christ's prayer for that conversion which is indispensable for "Peter" to be able to serve his brethren. I earnestly invite the faithful of the Catholic Church and all Christians to share in this prayer. May all join me in praying for this conversion!

We know that during her earthly pilgrimage the Church has suffered and will continue to suffer opposition and persecution. But the hope which sustains her is unshakable, just as the joy which flows from this hope is indestructible. In effect, the firm and enduring rock upon which she is founded is Jesus Christ, her Lord.