GENEVA (CNS) - Differences in moral teaching, especially regarding sexuality, are straining the unity of Christian communities and challenging efforts to overcome divisions among Christians, said a Catholic cardinal and an Armenian Orthodox catholicos.

Cardinal Walter Kasper, president of the Pontifical Council for Promoting Christian Unity, and Armenian Catholicos Aram I of Cilicia, moderator of the central committee of the World Council of Churches, spoke at a Nov. 17 celebration in Geneva on the 40^th anniversary of the joint working group of the council and the Catholic Church.

The catholicos said the 40 years marked "a journey of confidence building" as Catholics, Orthodox and Protestants learned more about one another and about the faith they hold in common.

He said the joint working group, rather than co-ordinating co-operation between the Catholic Church and the council, "has become mainly a joint study group" on theological issues.

While ecumenical study is important, he said, theological issues should be handled by the WCC.s Faith and Order Commission, which includes Roman Catholic members.

"In a world of uncertainties and tensions, people are increasingly expecting the churches' united voice," he said, and the joint working group is an appropriate body for developing common responses to concerns "immediately relevant to the life and witness of the churches."

"Our churches today are more divided in respect to moral, ethical and pastoral issues than doctrinal ones," he said. "They need guidance and help to heal the intrachurch and interchurch divisions on these questions.

"It is high time that we focus our attention on areas and concerns that touch the daily lives of churches and Christians," he said.

Kasper agreed that changes should be made to the joint working group, especially in response to the fact that "the ecumenical movement is today clearly in a transitional period" when Christians recognize each other's faith and are forming unions, but also face the danger of ignoring serious doctrinal differences out of impatience for unity.

"The Catholic understanding of unity - understood as full communion in faith, sacraments and church ministry - corresponds in principle with the understanding of our Orthodox and Oriental Orthodox sister churches, but unfortunately differs from the most usual interpretation of the mainline Protestant position," he said.

While theological discussions continue, Kasper said, Christians must engage in more "practical ecumenism" by praying together, serving the poor and speaking out together, serving the poor and speaking out together on social, political and moral issues that affect human life, dignity, peaceful coexistence and the preservation of creation.

"Over the years, the issues raised in the ecumenical debate have shifted from political ethics to individual ethics, especially in relation to sexual behaviour," the cardinal said.

"One may say that these questions are not the most important ones in the hierarchy of truths. That is true," he said, yet they have an "enormous emotional" impact and can lead to new divisions within Christianity.

The issues are not simply about abortion or homosexuality or marriage, he said, but about how Christians view the human person and how Christian communities read and interpret the Bible. Such issues are appropriate and important questions for Christians to explore together as part of their search for unity, he said.

Copyright 2005 by CNS reprinted with permission.