VATICAN CITY, JULY 1, 2004 (Zenit.org).- Christians must recover their lost unity to witness to the Gospel "in a more credible way," John Paul II and Orthodox Patriarch Bartholomew I say in a joint declaration.

The declaration, published today by the Vatican press office, culminated the visit of Orthodoxy's "first among equals" to Rome, on the occasion of the solemnity of the Apostles Sts. Peter and Paul, feast of the Rome Diocese.

"In the face of a world suffering all kinds of divisions and imbalances, today's meeting is an effort to recall in a concrete way and with force the importance that Christians and Churches live among themselves in peace and harmony, to witness concordantly the message of the Gospel in a more credible and convincing way," the declaration says.

"Many are the challenges to be addressed together to contribute to the good of society: to heal with love the wound of terrorism, to infuse a hope of peace, to contribute to cure so many painful conflicts; to restore to the European continent the awareness of its Christian roots," the two religious leaders continue.

In the statement, Orthodox and Catholics in effect commit themselves "to construct a real dialogue with Islam, because from indifference and reciprocal ignorance only diffidence and even hatred can ensue."

The text reaffirms the need to "nourish the awareness of the sacredness of human life" and to "operate so that science will not deny the divine spark that every man receives with the gift of life."

The Pope and ecumenical patriarch of Constantinople point out that the unity of Christians is also necessary "to collaborate so that this earth of ours is not disfigured and creation is able to preserve the beauty that God has given it."

But "above all" John Paul II and Bartholomew I indicate, it is necessary that Orthodox and Catholics be united "to proclaim with renewed commitment the evangelical message, showing contemporary man how much the Gospel can help him to find himself and to build a more humane world."

As a key step to advance on the path toward full unity between Orthodox and Catholics, separated by an almost 1,000-year schism, both the Bishop of Rome and the Patriarch of Constantinople decided to relaunch the work of the Mixed International Commission for Theological Dialogue between the Catholic Church and the Orthodox Church. The commission, established in 1979, is perceived as having lost its rhythm of work in recent years.

The Holy Father and the patriarch acknowledge that "problems and misunderstandings" from the past continue, as well as "fears" that have arisen recently given the changes that have taken place after the fall of the Communist regimes in Central and Eastern Europe.

Given these situations, the two Christian leaders repeated the advice that St. Paul gave to the Corinthians: "May everything be done among you in charity."

"The long practice of the 'dialogue of charity' comes to our aid precisely in these circumstances, so that the difficulties may be addressed with serenity and not slow down and darken the path undertaken toward full communion in Christ," the joint declaration concludes.

Bartholomew I's visit served to celebrate with John Paul II the 40th anniversary of the historic embrace in Jerusalem between Patriarch Athenagoras I of Constantinople, and Pope Paul VI.

Later, on Dec. 7, 1965, the day before the closing of the Second Vatican Council, Paul VI and Athenagoras I made a joint declaration deploring and lifting the mutual "anathemas" that gave rise to the 1054 schism between the Churches of the East and West.