Pope Benedict XVI, the spiritual leader of Catholic Christian all over the world, celebrated the Christ- mass at Saint Peter's Basilica on Tuesday and sent with this occasion a message of peace and unselfishness.

The mass was also held in the city were Jesus was born, where just like about 2000 years ago the security was very tight. Hundreds of policemen were deployed over the weekend to provide security for pilgrims, political and religious leaders arriving for the Christmas mass.

"This land of God cannot be for some a land of life and for others a land of death, exclusion, occupation, or political imprisonment. All those whom God, the lord of history, has gathered here must be able to find in this land life, dignity and security," said the Latin Patriarch Michel Sabbah in his sermon addressed in his native Arabic to thousands of Christians from all over the world.

Palestinian president Mahmud Abbas also participated at the mass just a month after attending the summit in the US city of Annapolis, where the process of peace in the Middle East was formally initiated.

Pope Benedict held his homily in Italian and the main point of focus was the selfishness. His Holiness explained that today’s people are so preoccupied with their selves, they have such urgent need of all the space and all the time for their own things, that nothing remains for others, for his neighbor, for the poor, for God. Saint Peter's Basilica packed with thousands of worshippers.

The other issue the pontiff emphasized in his message to approximately 1.1 billion Catholics was the need to take action against the degradation of the environment

Linking his message to homilies of the fourth-century Bishop Gregory of Nyssa who lamented a "universe torn and disfigured by sin," Pope Benedict asked: "What would he say if he could see the state of the world today, through the abuse of energy and its selfish and reckless exploitation?"

Earlier, the pontiff officially started the Christmas festivities by lighting a candle for world peace in a window overlooking St Peter's Square as this year's nativity scene was unveiled.