Regensburg, Germany - Pope Benedict held an open air mass on Tuesday in the town where he had hoped to spend his retirement and rejected the use of God's name to justify hatred and fanaticism.
Speaking to several hundred thousand people gathered in a field outside this Bavarian city, he also re-stated his position that science could not provide an explanation of the origins of the world that would exclude God's role.
The 79-year Pope, looking fit and wearing gold and white vestments on the fourth day of his trip home, celebrated mass from a huge altar platform topped by a white canopy.
An enthusiastic crowd estimated by police at more than 260,000 waved yellow and white Vatican flags as the Pope arrived. Organizers had expected up to 350,000 people.
The Pope said that Christians believed in a loving God who showed himself to the world in the person of Jesus Christ.
Christians had learned to recognize "the ways that God's image can be destroyed by hatred and fanaticism," he said.
"It is important to state clearly the God in whom we believe and to proclaim confidently that this God has a human face."
The Pope did not name any religion but in the past he has called on Muslim leaders to help defeat terrorism by teaching that violence could not be used in God's name.
Last week, he said no one had the right to use religion to justify terrorism and urged greater inter-religious dialogue to stop the cycle of hate and vendetta from infecting future generations.
On Monday, he prayed for the victims of the September 11 on the fifth anniversary of the attacks against the United States.
In his homily, the Pope also said attempts in history to deny God's existence through the use of reason had failed.
NO RETIREMENT ANYMORE
Regensburg is the medieval city where the Pope taught theology from 1969 to 1977 and hoped to return in retirement from Vatican service to write one last major theological work.
As Cardinal Joseph Ratzinger, he twice asked
Pope John Paul to let him retire from his job as the Vatican's top doctrinal official, but John Paul refused.
On Wednesday the Pope will spend what the Vatican calls a "private day" in the area which will include a visit to the house in the Regensburg suburb where he had hoped to retire.
"This is the event of the century here," said Elfriede Sontag, 54, who attended the mass with her family.
"Having a Bavarian Pope is a great feeling. In a way this is about the atmosphere and being together rather than about being too serious about religion," she said.
In another section of his homily, the Pope also spoke of the relationship between science and religion.
He said that since the enlightenment in the 18th century, some sectors of the scientific world had tried to seek "an explanation of the world in which God would be unnecessary."
He added: "When God is subtracted, something does not add up for man, the world, the whole vast universe."
Reiterating some of his past statements, Benedict dismissed the notion that man and reason could be "nothing more than a chance result of evolution."
On Tuesday afternoon the Pope was due to deliver a major lecture to scientists at the university where he once taught and preside at an ecumenical vespers service with representatives of other Christian denominations and local Jewish leaders.