Pope Benedict XVI and representatives of the world’s major religions will make speeches and sign a common commitment to peace when they meet in Assisi in October, but they will not pray together, the Vatican has said.

In fact, Pope Benedict’s formal prayer service will be held at the Vatican the evening before the encounter in Assisi with leaders of other Christian communities and representatives of the world’s main religions.

The October gathering will commemorate the 25th anniversary of Pope John Paul II’s “prayer for peace” encounter in Assisi. The 1986 event was seen by many as a milestone in interreligious relations but was criticised by some Catholics who said it appeared to inappropriately mix elements from Christian and non-Christian religions.

The Vatican press office issued a statement giving the theme for the 2011 event – “Pilgrims of Truth, Pilgrims of Peace” – and a general outline of events.

“Every human being is ultimately a pilgrim in search of truth and goodness,” the Vatican statement said.

The search requires people to enter into dialogue with others, “believers and unbelievers alike, without sacrificing one’s own identity or indulging in forms of syncretism” where elements of different religions are used indiscriminately, the statement said.

“To the extent that the pilgrimage of truth is authentically lived, it opens the path to dialogue with the other, it excludes no one and it commits everyone to be a builder of fraternity and peace. These are the elements that the Holy Father wishes to place at the centre of reflection,” the Vatican said.

The statement said Pope Benedict will prepare for the Assisi gathering by hosting a prayer service with Catholics from the Diocese of Rome in St Peter’s Basilica the evening before.

Other Catholic dioceses and other Christian communities are encouraged to organise similar prayer services, the statement said.

The Vatican said the Pope was inviting to Assisi representatives of other religions, other Christian communities and representatives of the worlds of culture and science who do not profess a religious belief, but who “regard themselves as seekers of the truth and are conscious of a shared responsibility for the cause of justice and peace”. The pontifical councils for interreligious dialogue, for promoting Christian unity and for culture are distributing the invitations.

Pope Benedict and other participants will take a train to Assisi on the day, the statement said.

After speeches in the Basilica of St Mary of the Angels, there will be a simple lunch, followed by “a period of silence for individual reflection and prayer”.

In the afternoon, participants will go in pilgrimage to the Basilica of St Francis, the saint’s resting place, where they will make “a solemn renewal of the joint commitment to peace”, the Vatican said.