VATICAN CITY, DEC. 21, 2004 (Zenit.org).- John Paul II told his aides in the Roman Curia that unity among all people, beginning with believers, is his foremost concern and commitment.

"Unity of the Church and unity of the human race! I read this aspiration to unity in the faces of pilgrims of all ages," the Pope said today when meeting with Curial officials in the traditional meeting to exchange Christmas greetings.

The Holy Father recalled that the Second Vatican Council constitution "Lumen Gentium" stated that the Church has the "mission to be a sign and instrument of profound union with God and of the unity of the whole human race."

He appealed to the cardinals, bishops, priests, religious and lay people present "to be ever more aware that communion with God and unity among all people, beginning with believers, is our priority commitment."

John Paul II said that "it is urgent to rebuild full communion among Christians." This was the reason he convoked the Year of the Eucharist: "Among other things, it seeks to make even more intense this thirst for unity, presenting the unique and inexhaustible source: Christ himself."

He added that "the ecumenical effort is being intensified at different levels, thanks to constant contacts, meetings and initiatives with our brethren of the different Churches and Orthodox and Protestant ecclesial communities."

In this connection, the Pontiff mentioned some of the year's key ecumenical moments.

There was the visit to Rome last January of an ecumenical delegation of Finland, headed by Lutheran Bishop Eero Huovinen of Helsinki, on the occasion of the Week of Prayer for Christian Unity.

The visit also marked the fifth anniversary of the signing by Catholics and Lutherans of the Joint Declaration on the Doctrine of Justification.

This year also saw strong impetus given to the dialogue between Rome and the Ecumenical Patriarchate of Constantinople, as confirmed by the two visits that Orthodox Patriarch Bartholomew I made to the Vatican, the Pope said.

The patriarch's first visit was to participate in the feast of Sts. Peter and Paul, in June, and the second, just under a month ago, to receive from the Pope the relics of Sts. Gregory Nazianzen and John Chrysostom.

John Paul II further said he himself heartedly desired that "the return of the icon of the Mother of God of Kazan to Russia might contribute to speed up the unity of all the disciples of Christ."

The icon was returned in his name last August to Russian Orthodox Patriarch Alexy II by Cardinal Walter Kasper, president of the Pontifical Council for Promoting Christian Unity.

The Pope said that in two especially representative moments he perceived in pilgrims' faces this search for the unity of the Church and of all people: during the meeting of Catholic young people of Switzerland, which he attended in June, and Catholic Action's mass meeting in Loreto, Italy.

"Believers have a great responsibility, especially to new generations, to which the Christian heritage must be transmitted in an unaltered manner," the Pope said. "For this reason, on several occasions -- especially during the pilgrimage to Lourdes -- I did not fail to encourage European Catholics to remain faithful to Christ."

To promote unity among men, the Holy Father gave the same charge to cardinals that he left in his message for the forthcoming World Day of Peace: "Do not be overcome by evil, but overcome evil with good."

John Paul II ended his assessment of 2004 by assuring that, like all Christians, he is "not afraid of difficulties" because he trusts in the Child of Bethlehem, "who out of love comes into our midst."