Pope Benedict celebrated mass Sunday to open a worldwide meeting of prelates at the Vatican. Over 200 bishops are attending the gathering that will discuss the relevance of the Bible for contemporary Catholics. But no bishops from mainland China will be present. Sabina Castelfranco reports from Rome

To mark the opening of the second synod of bishops since his election in 2005, Pope Benedict celebrated mass Sunday at Rome's Basilica of Saint Paul Outside the Walls. More than 250 bishops from around the world will be taking part in the three-week meeting to discuss the relevance of the Bible for contemporary Catholics.

The Vatican said this week that no bishops from mainland China would be attending the meeting, a clear sign there has been no breakthrough in the Vatican's efforts to improve relations with Beijing.

The synod is a consultative body created in 1965 to facilitate contacts among bishops and to help the pope set policies for running the Church. At this meeting, bishops will exchange their views on  "The Word of God in the Life and Mission of the Church."

In his homily, the pope called on the Lord to assist all those taking part in the meeting to question themselves on how to make announcing the Gospel more effective in these times.

A document prepared for the synod rejects a fundamentalist approach to the Bible and says a key challenge is to clarify for the faithful the relationship of scripture to science.

For the first time, a non-Christian will be addressing the assembly. Israel's Shear-Yashuv Cohen, Grand Rabbi of Haifa, will speak on Monday about how the Jewish people read and interpret the Holy Scripture.

Cohen has said his invitation to address the synod of Catholic bishops was a "signal of hope bringing a message of love, coexistence, and peace for generations."

Protestant and Anglican prelates are also attending the gathering as observers. For the first time, the head of the Greek Orthodox Church Bartholomew the First will be giving a speech on October 18.