Pope Benedict XVI has celebrated the final open-air mass on a tour of his native Germany in a park outside the southern city of Regensburg.
The Pope was greeted enthusiastically near Regensburg
In his homily in front of more than 250,000 people, he spoke against the use of God's name to justify hatred and fanaticism.
The Pope again warned against an excessive reliance on science.
He said that a purely mathematically ordered cosmos would be nothing more than the chance result of evolution.
Pope Benedict XVI, 79, still has a house in Regensburg in Bavaria, some 120km (75 miles) north-east of Munich, where he taught theology in the 1970s.
He celebrated mass from a huge altar platform in a park near the town, and was greeted by an enthusiastic crowd waving Vatican and German flags.
Devout Catholics, among them altar boys, attend the open-air mass
The Pope spoke of the ways in which God's image could be destroyed by hatred and fanaticism, without mentioning any religion.
He reiterated the position of the Catholic Church on the relationship between science and religion, saying that since the 18th Century, some scientists had tried to seek an explanation of the world that excluded the presence of God.
"When God is subtracted, something does not add up for man, the world, the whole vast universe," he said.
The Pope will round off his visit by spending time with his older brother Georg, a retired priest who still lives in the Regensburg area.