It's a sign of the times, perhaps, that Gareth Richards has erected a disclaimer on stage, outlining that if you're of a religious disposition, this might not be for you, no hard feelings.

For the amiable comic may have rejected the evangelical Christianity of his adolescence. But he retains his manners and even his religion, after a fashion. It was so deeply ingrained in him as a child, how could he not? This is a show that takes issue with blind dogmatism rather than individuals with faith.

He went to church every Sunday for 20 years yet hasn't been once for the last 15, marvelling at the different person he was then. Christianity was the family business and is still preached by his father, whose own father, a Welsh coal miner, was visited by God during the Second World War and told to start a new church in a promised land. Which was a scout hut in Slough. A quick Google reveals that this born again organisation is still thriving, with outposts across the world.

Subtextually, there's presumably been a fallout in the Richards family about his loss of faith, but it's not something the comic chooses to dwell upon. Strumming one of his obscure but signature instruments, the QChord, Richards leads his congregation in a mantra of repeatedly chanting about his comic abilities and illustrates his points with the retro technology of the overhead projector.

Although it might have been easy and perhaps more creatively satisfying for him to play the renegade preacher given the oratory and musical talent at his disposal, Richards doesn't really pursue this mock sermon idea, tub thumping not his style.

Instead, he simply pits the literal word of the Bible against some of the more extreme, evangelical interpretations of it, reading the passages about Onan and Sodom verbatim, teasing out the ridiculousness and contradictions, awed that anyone might use them as the basis of doctrine about masturbation and homosexuality. The former inspires a brief bluegrass number, a typically melodious tune that reiterates the logical fallacies of a vengeful god supposedly denouncing young boys for jerking off.

At his strongest, he likens blinkered adherence to the Word as merely a variation on the 'just following orders' defence of the Nazis and points to the positive effect on suicide rates in US states that have permitted gay marriage. Mostly though, he's like a retired footballer now working as a pundit, invested but detached. He recalls the vainglorious, graphic Christian mime he performed to his baffled schoolfriends as if it were from another life, an episode he reprises for his daft finale.

Given the importance that religion had in Richards' life, this is an oddly lightweight and insubstantial offering. It feels as if he's pulling his punches, perhaps out of respect to his family, with only a sketchy depiction of his formative years and a surprising paucity of his trademark songs. His career feels like it's drifting a bit and perhaps he could do with some of his grandfather's fire and brimstone purpose to get it kickstarted again.