About 40,000 young people are expected to gather Dec. 28-Jan. 1 for the event in Zagreb, Croatia.
In his letter the Pope states: "All of you meeting in Zagreb, continuing the pilgrimage of trust on earth launched by dear Brother Roger, may become more and more aware of the importance of brotherhood among people and the necessary openness to all people around you.
"In this way, in a renewed attentiveness to others, you will make your contribution to the establishment of more fraternal relationships, so that on the entire planet the human family may become a concrete reality, where each person is welcomed and loved for him or herself, recognized and respected as a child of God."
The papal message continues: "In this land of Croatia, marked by conflicts in the past, you are an eloquent sign of hope and you demonstrate that you, the young, want a new humanity based on the recognition of all people, independent of their nationality or their religion.
"As Christians, marked by the one baptism that makes us all sons and daughters of the same Father, you are called to show that the Gospel message is universal and comes to meet every human being on the road of his or her life.
"By the way you consider others, by your attentiveness to each one, may you make Christ present, who calls you to love and to act like him. In this way you will be truly free and you will live out your human and Christian responsibility."
The Taizé Community was founded by Brother Roger Schutz. He was stabbed to death Aug. 16, 2005, by a mentally unbalanced woman during a prayer meeting.