‘This is edgy. Fucking edgy!’ Mark Ravenhill’s crazed film director tells his prospective star as he comes to a particularly tasteless part of his increasingly ludicrous plot. Product: World Remix, a new production of Ravenhill’s play, which he first performed at the Edinburgh Fringe in 2005, consists of an extended pitch for a sexually explicit political thriller that does not so much court controversy as strip naked and leap uninvited into controversy’s bed.

Jo Lobban plays the literally speechless actress the director wants for the lead, listening, smoking, sometimes appearing interested and sometimes simply appalled as Ravenhill works his way through the treatment, not simply by reading, but ‘acting’, singing, emoting and using his whole body to convey to true awfulness of the plot. Basically, the lead falls in with an Islamist terrorist and finds herself taking part in a dastardly operation involving Osama bin Laden, Eurodisney, a training montage set in Tibet, and a single-handed assault on Guantanamo Bay. The treatment of Islam alone would probably make the film a commercial disaster, but frankly that would be the least of its problems.

The show is entertaining, and Ravenhill’s performance titanic, and there are some nice jokes sending up the preoccupations of the media class. (The terrorists’ targets include, ‘The Hague, the Reichstag, Tate Modern.’) The basic problem with the piece is that a pitch for a dreadful film does not readily lend itself to good theatre, and the final third suffers as the initial joke starts to wear thin. It might have helped if Lobban’s actress had been made to speak for the audience as it were, raising objections for the director to respond to rather than simply letting him burn himself out. The idea of the second character never speaking is a nice conceit, but not at any cost. Ultimately the effect is to heighten the cringe-value of Ravenhill’s performance at the expense of any exploration of the themes raised by the film’s plot. Given the difficulty of saying anything sensible about these, however, this in itself may be no bad thing.

Product is paired with What Would Judas Do?, another show performed by its writer. Stewart Lee is probably best known as the co-writer of Jerry Springer the Opera, which famously attracted protests from eccentric but voluble Christians when it was shown on BBC television at the beginning of 2005, because of its portrayal of Jesus. That experience, which involved threats of damnation as well as censorship, has clearly not put Lee off dealing with Christianity in his work. What Would Judas Do?, a sort of alternative gospel, is less a provocation or a show of defiance, however, than an attempt to get to grips with religion from the point of view of a practical-minded man with little patience for superstition. Like Howard Brenton’s Paul, but funnier, it is a secularised version of a Christian story. Lee takes the fairly well-established view that Judas was really a Jewish rebel looking to get the Romans out of Judea, and ultimately disappointed to find that Jesus was not the man for the job. (He might have been rather more impressed by Paul, if they’d only met.)

Judas shuffles onto the stage in scruffy attire, introduces himself and embarks on lecture-cum-stand-up routine recounting the events of the final week building up to the crucifixion, with bags of nuts as rewards for audience-members who are able to help. Lee is at ease with the audience, and able to respond in character. At one point, Judas asks if anyone knows who Mary Magdelene was, clearly looking for the answer, ‘a prostitute’. (‘His girlfriend? Well, yeah, if you can have a girlfriend that you pay’.) When one woman at the performance I attended said Jesus had exorcised spirits from Mary Magdelene, Judas/Lee hesitated, as if wondering if he might have missed this, before shaking his head: ‘No’, and then another shake of the head and a facial shrug, as if to convince himself, before he moved on to a hilariously unconvincing polemic about the socio-economic status of prostitution. As Lee probably knows, according to Luke (8:2), Jesus did cast seven devils out of Mary, but the beauty of the show is that Judas is not bound by any of the (sometimes mutually contradicting) gospels. This is his version, and it is refreshingly free of supernatural complications.

Indeed, Judas is not enamoured of his fellow disciples, especially Matthew and John, a pair of stuck-up intellectuals who always sniggered when he asked Jesus for clarification on this or that cryptic declaration. As a stuck-up intellectual myself, I was not at all convinced by Judas’ pedantic objection to putting Jesus on a donkey to enter Jerusalem in order to fulfill a prophecy, however. ‘It’s not fulfilling the prophecy if you do it deliberately,’ he protests, surely revealing political naïveté as much as literal-mindedness. More generally, though, it is hard not to sympathise with Judas, and share his consternation at his fellow disciples’ unquestioning assent to the Messiah’s often bonkers utterances, not to mention His refusal to think strategically. It is the same frustration felt by anyone struggling to come to terms with religion and its apparent acceptance by people who simply could not function if they truly followed its teachings.

Of course, human frailty is at the heart of religion, and anyone wanting to understand it has to be comfortable with contradiction and paradox. The tragedy of Stewart Lee’s Judas is neither that Christianity is irrational nor that he is too stupid to understand it, but simply that he has nowhere else to go. Having finally failed to provoke an uprising by helping the Pharisees to kill Jesus, he can only kill himself. (Judas makes it clear from the beginning that there are no unexpected plot twists, so I’m not giving anything away.) The audience is left to reflect on what has happened, wandering off into the night clutching our scraps of Last Supper bread, and nuts if we’re lucky, to face a world in which the questions that vexed Judas are still largely unanswered. What would Judas do? What could Judas do? This is the funniest treatise on these questions since the Sermon on the Mount.