John Paul II, ecumenist asks prayers for his own conversion.

Future historians, asked to name John Paul 11's most influential achievement, would surely have pointed to his role in dismantling the late Soviet empire. But now, following the publication of his new encyclical, Ut unum sint ("That They May Be One," see, Origins, June 8), there is another choice for their consideration. The encyclical may mark the beginning of the end of Christianity's thousand-year division.

John Paul reminds his readers that the Roman Catholic church committed itself to ecumenism "irrevocably" at Vatican II. As if to show how much of the council's vision still goes unrealized, however, he takes most of his quotations in Ut unum sint from Vatican II's Decree on Ecumenism (I 964). He writes with a sense of urgency "to encourage the efforts of all who work for the cause of unity." While much of this essentially pastoral encyclical is taken for granted in ecumenical circles, its truths have not permeated the Roman church's everyday consciousness. John Paul is determined that they do so.

No disciple, he argues, can remain indifferent to ecumenism: "To believe in Christ means to desire unity; to desire unity means to desire the church; to desire the church means to desire the communion of grace which corresponds to the Father's plan from all eternity." Every Christian can and must work for unity by prayer, both individual and common, by conversion, and by "every possible form of practical cooperation at all levels." Though he does not quote it, John Paul makes his own the famous question of the Third World Conference on Faith and Order (Lund, 1952): "Should not our churches ask themselves ... whether they should not act together in all matters except those in which deep differences of conviction compel them to act separately?"

The goal of the ecumenical movement, writes John Paul, is the full communion of faith and life that is realized and celebrated in sharing the Eucharist. Ecumenism is intrinsic to the essence and mission of the church. The church of Christ cannot be a sign and sacrament of unity, as Vatican 11 said it was, as long as it remains divided. To the extent that Christians are walled off from one another in their own denominations, the gospel of unity is not credible. Unity does not mean uniformity. It does not require that every church and every Christian use the same formulae to profess the one faith: "The expression of truth can take different forms."

Near the end of his letter, however, John Paul goes beyond the conventional to extend an epoch-making invitation: "Could not the real but imperfect communion existing between [sic] us persuade church leaders and their theologians to engage with me in a patient and fraternal dialogue on this subject [of the primacy of the bishop of Rome] ... ?" He cites ecumenical agreements that indicate that the authority of the bishop of Rome is not the real obstacle to reunion, but rather the way that authority has been exercised. So John Paul asks forgiveness of other Christians, acknowledges their "painful recollections," and says that to make his own ministry "a service of love recognized by all concerned" is an "immense task" which "I cannot carry out by myself." Thus, his unprecedented and revolutionary invitation in the encyclical to a dialogue aimed at the reform of his own ministry.

How can this extraordinary encyclical be squared with those documents, decisions, and appointments that have deeply troubled ecumenists during the seventeen years since John Paul II's election? For instance, it took the Vatican over ten years to respond to the 1982 Final Report of the first Anglican-Roman Catholic International Commission. When a response finally came, it seemed to repudiate the commission's method, which John Paul himself had commended, and to require Anglicans to accept Roman Catholic doctrinal formulations. Ecumenical leaders saw the 1992 letter on the church as communion, which John Paul formally approved, as a new version of the "ecumenism of return," where unity is achieved by absorption of the other Christian churches back into Roman Catholicism. His encyclical Veritatis splendor, written to the bishops and not with them, seemed to narrow the church's teaching authority to himself. Many have been troubled by the choice of bishops (in Switzerland, the Netherlands, Austria, El Salvador, the United States), selected apparently more for their theological conformity than for their ability to represent and nurture the faith of their people.

John Paul's dramatic invitation may have been prompted by the imminence of the year 2000. Late last year he issued Trente millenio adveniente ("As the Third Millennium Approaches" , where he said that preparing for the year 2000 had become "a hermeneutical key to my pontificate." The chief purpose of the millennial jubilee, wrote John Paul, is "the strengthening of faith and of the witness of Christians." But that witness is crippled so long as the churches are divided from one another.

Now, apparently, he has decided that action is necessary. Since, as Paul VI said, "The pope, as we well know, is undoubtedly the gravest obstacle in the path of ecumenism," it is obvious where action could be most effective. John Paul's longing for renewed Christian witness in the year 2000 has intensified his commitment to unity. Yet he knows there can be no unity without reform of the office he holds. He asks for help in this essential, monumental task.

He offers a preview of a reformed primacy by speaking of himself only as successor of Peter, bishop of Rome, and, most emphatically, as servus servorum Dei ("servant of the servants of God" . Titles like patriarch of the West, Holy Father, Vicar of Christ, and even pope do not appear in this encyclical. The designation "servant of the servants of God," he writes, is "the best possible safeguard against the risk of separating power (and in particular the primacy) from ministry." Ut unum sint again and again emphasizes the collaborative, collegial dimension of the office. John Paul highlights conversion as the heart of the ecumenical enterprise, but stresses his own conversion first and foremost. He even asks his fellow Christians to pray for his conversion so that he might carry out his ministry of service.

Although the church of Christ subsists in the Roman Catholic church, it needs the other churches, just as they need it. Other churches played an important role in crafting key documents of Vatican 11. So also, the indispensable reform of the primacy will not be the accomplishment of the Roman Catholic church alone.

Some will fault the encyclical for overlooking "interchurch" marriages (about which John Paul has been eloquently positive). Others will criticize its unnecessarily gender-specific terms. Still others will wish for a further development of his remarks on the Christian martyrs of the different churches, fully united with Christ and therefore with one another. Yet Ut unum sint remains an extraordinary opportunity. If ever there was an ecumenical kairos, this is it.

Jon Nilson is associate professor of theology at Loyola University Chicago and serves on the Anglican-Roman Catholic Consultation in the United States.