An international expert on church unity has urged the Roman Catholic Church to declare officially that its excommunication of Martin Luther no longer applies.
Such a statement, "in these ecumenically less exciting times ... would be a remarkable step and a sign of hope and encouragement", said the Rev Günther Gassmann, a German Lutheran theologian, who was director of the World Council of Churches' Faith and Order Commission from 1984 to 1995.
Born in 1483, Luther trained as a Catholic monk, but was excommunicated by the Catholic Church in 1521 after refusing to retract teachings the church judged to be heretical.
In a 19 March lecture in Rome, Gassmann said that a joint Lutheran-Catholic statement published in 1983 to mark the 500th anniversary of Luther's birth had sought to elaborate a common position on the work and legacy of the reformer.
"Luther, a major symbol and personification during 400 years of the past Catholic-Lutheran conflict and division, is now seen as a common teacher," Gassmann noted, at the Centro Pro Unione, an ecumenical research centre in the Italian capital.
He urged the Catholic Church to receive officially, "this changed evaluation of Martin Luther".
In 2008, the Vatican's top official for Christian unity, Cardinal Walter Kasper, encouraged Catholics to read Luther's hymns, which he declared were "full of spiritual power", and his commentaries on the Bible.
"One will then discover a Luther who is full of the power of faith, whom one cannot simply make Catholic, whom we find provoking and even alien in many respects, but from whom even Catholics can learn," said Kasper, president of the Pontifical Council for Promoting Christian Unity since 2001.
Gassmann presented an overview of the results of Catholic-Lutheran dialogue from 1965 to 2005. He praised the 1999 signing by the Catholic Church and the Lutheran World Federation of a Joint Declaration on the Doctrine of Justification as a "unique" event.
This represented, he said, "an agreement concerning the most fundamental theological difference between Catholics and Lutherans at the time of the Reformation and ever since".
It was the first, and so far only, time that the Catholic Church and one of its dialogue partners have officially confirmed the results of a bilateral dialogue, Gassmann added.
Gassmann noted that Cardinal Joseph Ratzinger - now Pope Benedict XVI - had been involved in the latter stage of talks that led to the signing of the declaration.
"The Joint Declaration continues to act as an impulse and encouragement of both initiating and intensifying Catholic-Lutheran relationships in many places of the world," he said, also drawing attention to the acceptance of the statement by the World Methodist Council in 2006.
Gassmann urged the LWF, a global grouping of Lutheran churches, and the Vatican's Christian Unity council to set up a special group to evaluate results of Catholic-Lutheran dialogue with a view to them being submitted for "official reception and affirmation".
These included statements on the Eucharist and on other issues that have divided the Lutheran and Catholic churches, such as the nature of ordained ministry. Although differences remain, "We can speak of a far-reaching agreement on the doctrine and practice of the Eucharist. This represents a significant result," said Gassmann.
"This [official affirmation] would have an enormous impact on our churches," said Gassmann. "This would inspire ecumenical hope and confidence in our time."
[With acknowledgements to ENI. Ecumenical News International  is jointly sponsored by the World Council of Churches, the Lutheran World Federation, the World Alliance of Reformed Churches, and the Conference of European Churches.]