Tony Blair has defended religious faith as a force for good in the world during a televised debate with atheist and columnist Christopher Hitchens.
The former prime minister said it was true that "people commit horrific acts of evil in the name of religion".
But Mr Blair, who converted to Catholicism in 2007, said it was also true that religion inspires acts of extraordinary good.
And he said it was important not to condemn all people of religious faith because of the "bigotry or prejudice shown by some".
Mr Blair also told the 2,700-strong audience in Toronto, Canada, the invasion of Iraq was "not about religious faith" but decisions on the war were "based on policy".
He said it was "futile" to try to "drive religion out" and it was more important to concentrate on how to get people of different faiths to work together, particularly in the Middle East where the conflict would only be resolved if people worked across the "faith divide".
Sceptic Mr Hitchens, who has terminal cancer, likened God to a "celestial dictatorship, a kind of divine North Korea".
He appeared to win over the audience, which voted two-to-one in his favour following the debate, which argued the motion "be it resolved, religion is a force for good in the world".
Mr Blair, 57, who became a practising Christian while studying at Oxford University, said: "It is undoubtedly true that people commit horrific acts of evil in the name of religion. It is also undoubtedly true that people do acts of extraordinary common good inspired by religion."
He pointed to the good done by faith based organisations, including the millions of lives saved in Africa and care for the mentally ill, disabled and destitute, adding: "The proposition that religion is unadulterated poison is unsustainable. It can be destructive, it can also create a deep well of compassion, and frequently does."