Pope Benedict opened a major Vatican meeting today by decrying a modern culture so devoid of faith that some people were declaring God 'dead' and entire nations were losing their identity.
The 81-year-old German pope made his comments in the homily of a mass opening a month-long synod of Roman Catholic bishops from around the world who will be discussing God's message through Scripture.
He said nations that were "once rich in faith" were now "losing their identity under the harmful and destructive influence of a certain modern culture".
Since his election in 2005 the pope has been condemning a loss of Christian identity in most developed countries in Europe and has recently been speaking out about the need to re-inject moral values into Europe's political arena.
"There are those, who, after deciding that 'God is dead,' declare themselves to be 'god' and the artisan of their own destiny, the absolute master of the world," he said.
Attempts to "brush God aside" lead to arrogance of power, selfishness, injustice, exploitation and violence, he said at the Basilica of St Paul's in Rome.
"When men proclaim themselves to be absolute masters of themselves and sole masters of creation, can they truly build a society where freedom, justice and peace reign?," he said.
The synod, whose formal work begins on Monday, will be discussing scripture and will break new ground when Rabbi Shear-Yashuv Cohen becomes the first Jew to address such a Vatican gathering.
But it has been marred by Beijing's denial of permission for Catholic bishops to travel to Rome for the event.
China's communist government does not allow its Catholics to recognise the pope's authority and forces them to be members of state-backed Catholic organisation.
China's eight to 12 million Catholics are split between the officially approved church and an "underground" one loyal to the pope.
The lack of participation from China came as a surprise because there had been signs of improved relations this year.
A bishop from Hong Kong represented Pope Benedict at the opening ceremony of the Olympics in August and in May China's national orchestra played for the pope at an unprecedented concert in the Vatican.
Benedict has made improving relations with China a main goal of his pontificate and hopes diplomatic ties can be restored.
China says that before restoring ties that were broken off two years after the 1949 Communist takeover, the Vatican must first sever relations with Taiwan, which Beijing considers a renegade province.
Bishops from Macao and Honk Kong, regions with a degree of autonony from Beijing, will attend.
In an event related to the synod, the pope will be the first of some 1,200 people to take part in a marathon non-stop reading of the Bible expected to last a week and be broadcast on Italian state television RAI.
The pope will read from the book of Genesis. Rome's chief rabbi, Riccardo di Segni, had been expected to read immediately after the pope but pulled out of the event last month, saying it had become "too Catholic".
All 73 books of the Catholic edition of the Bible will be read. Each speaker will read for about 5-8 minutes on live TV.