Lord Ian Blair has warned that violence, infighting and abuse are obscuring much of the good that people of faith are doing in the world today.

The former Commissioner of the Metropolitan Police said last night that religion was behind some of the intolerance and violence seen in the world today.

He warned that people were not always aware of the achievements brought about by religion because of some of the crimes committed by people of faith as well as internal conflicts, for example within his own Anglican Church.

“The greatest achievements and ambitions of human social history, such as the abolition of slavery and the provision of universal education or free health care for all have had their origins in religious impulse. This is not the image of religion in this past century or this past decade,” he said.

"The horrors of clerical child abuse and the arguments over homosexuality... are obscuring the basic decency that comes from the commandments to peace contained in all religions, a commandment which in the Christian church, for instance, requires each member of a congregation at every service to greet his or her neighbours with the words 'Peace be with you’.”

Lord Blair, a practising Anglican, went on to say that Islam had been “demonised” by the terrorist acts committed by Islamic extremists and that to most people, faith appeared “irrelevant, clannish, prejudiced, old-fashioned and violent”.

Speaking at the annual lecture of theology think tank Theos, Lord Blair went on to say, however, that he believed religion was still principally a force for good and that the acts of charity and love by people of faith “should be and remain the glue that permits modern society to exist”.

He said such good deeds by the faithful were the “bulwark” of public order and could help foster “tranquillity” in wider society.

However he argued that people of faith needed to shed some of their own certainty about being right, saying that doubt could be a counterbalance to “shrill conviction”.