I don't do God and I don't like things that some of those who do God do. Bombing Iraq, for instance. Demanding exemptions from the law on grounds of conscience. Then there's stoning women, killing gay people, and abusing children and covering up for it. What else? How about book-burning, witch-trialing and poison-spreading? Not nice. I take exception, too, to Jehovah's Witnesses knocking when I'm in the bath, expecting a nice parcel from the postman, or both. Even God wouldn't like that. Yet I won't be boarding the atheist bus. Why? Because I'm not sure I'd enjoy the company.

Pious atheism gets up my nose: not right up, but far enough for me to catch a whiff of sanctimony I rebel against instinctively. There's been something glib about the attacks on faith and its subscribers that's such a feature of the post-9/11 years, not least at Comment is free. That said, it's nothing new. The paradox of religions preaching love and practising hate is among the first of life's many big contradictions we encounter. Homilies about more people being killed "because of religion" than anything else are widely encountered by age ten. Debates between sixth-formers follow. Few that take place among grown-ups, whether egg-heads or oiks, are less callow.

Much deriding of religion is smug, rooted in stereotypes and suffused with a presumption of intellectual superiority that is rarely justified. It is as unenlightened in its way as those it scoffs at. Its standard mockery is that believing we are beholden to some bearded bloke in the sky is laughable at best and ultimately dangerous both to the individual and society. This is true insofar as the presence of religion in human cultures can be reduced to such a characterisation. But often it cannot.

The great irony is that much derogation of religion comes from ardent rationalists and from the left. These see religion only as a form of ignorance and a force for psychological diminution imposed by conservative powers from above. But while religion can quite obviously be all of those things and has been throughout history, it really isn't as simple as that. By presuming that people are only repressed by faith or in thrall to it, its devoted critics bear a depressing resemblance to the irrational and to the right.

To use the jargon of social studies, they ignore individual "agency." In their indignant certainty, they miss the blindingly, empirically obvious, such as that individuals relate to their faiths in individual ways and in differing degrees according to need, circumstance and personal taste. For some, observance is merely a cultural custom that co-exists comfortably with a general humanism and a secularist view of government, the law and the state. Their religion can provide moral metaphors, a link with family history or mystical spaces for contemplation involving little if any subservience to unaccountable hierarchies or deference to reactionary dogma. God is what people make him and there are some examples of this creativity from which the left could learn a great deal.

On Wednesday evening I took a half hour walk from my home to the York Hall in Bethnal Green, an East End landmark famous for its baths and as a boxing arena. On this occasion, though, it was hosting a gathering of Telco, the east London component of an organisation called London Citizens. This capital-wide coalition of faith groups – everyone from Methodists to Muslims - supported by trade unionists and others, promotes and prosecutes an impeccably progressive agenda of social activism which includes the London Living Wage and earned citizenship for over-staying immigrants, both of them opposed by the government.

Their size and energy make them impossible for politicians and others in power to ignore, as Boris Johnson learned during the mayoral election campaign and one of his deputies, Richard Barnes, the Labour leader of Tower Hamlets council and three Olympic bigwigs can now confirm. The hall was packed, amiable and insistent. Would I share all those peoples' values? I'm sure I wouldn't. Yet their desire to build bridges, their hunger for fair play and their boundless optimism are precisely what is lacking from the politics of social justice these days. For some, religion has become a convenient culprit for the ills of the modern age. Much too convenient, I'm afraid.