, knowing that whenever societies have tried to pretend God did not exist, tragedy followed, Pope Benedict XVI said.

Pope Benedict make his remarks Dec. 14 during a morning audience with civic leaders and pilgrims from the town of Pescopennataro and the province of Isneria, which donated the 78-foot silver fir tree that became the Christmas tree in St. Peter's Square.

Apparently informed that Pescopennataro has a population of about 350 people, the Pope seemed a bit surprised at the crowd of 450 people who came to pay their respects and receive his thanks for the gift of the Christmas tree.

"The whole town must be here," he told them.

In fact, the mayor did manage to get everyone on buses and to the Vatican. Along with regional government officials, they met with the Pope just a few hours before Bishop Giuseppe Sciacca, secretary-general of the office governing Vatican City, presided over the official tree-lighting ceremony.

At the ceremony, the Pescopennataro poet, Angelomaria Di Tullio, read in the local dialect a poem he wrote about the tree, growing for decades near his hometown so that one day it proudly would represent the Pescolani people at the Vatican.

At the audience earlier, Pope Benedict said the gift of the tree was a sign of the faith and religiosity of the southern Italian communities that donated the tree for St. Peter's Square and smaller trees for the Apostolic Palace.

Isaiah prophesied the coming of the Messiah as "a great light for the people who walked in darkness," the Pope said. "God became human and lived among us to scatter the darkness of error and sin, bringing humanity his divine light."

"This great light -- of which the Christmas tree is a sign and a reminder -- not only hasn't dimmed with the passing of centuries and millennia, but continues to shine on us and enlighten each person who comes into this world, especially when we go through moments of uncertainty and difficulty," the Pope said.

Throughout history when dictators and ideologues have "tried to extinguish God's light," he said, "periods marked by tragic violence" and attempts to destroy human beings followed in their wake.

"This is because when one tries to cancel the name of God from the pages of history," real values and real meaning are skewed, Pope Benedict said. "Think about words like 'freedom,' 'common good,' 'justice': deprived of their rootedness in God and his love, in the God who showed his face in Jesus Christ, these realities often end up at the mercy of human interests, losing their connection with the requirements of truth and civic responsibility."