It is perhaps appropriate that a new Danish collection of Jesus and Mo cartoons should be published this week, the tenth anniversary of publication of the original Danish cartoons. This is the foreword that I have written for the new collection.

Satire can be a deadly business these days. Especially for those satirists who see it as their business to mock religion. And most especially for those who dare to mock Islam.

The murderous assault on the Paris office of Charlie Hebdo in January this year, followed by the attack at the Krudttønden cafe in Copenhagen during a debate featuring Lars Vilks, the Swedish artist known for his controversial depictions of Mohammad, reveal the furies that now often confront cartoonists. Against this background, it takes courage to be a satirist of religion. We should be grateful simply for the existence of Jesus and Mo. The author may be forced to remain anonymous, but the fact that the cartoons come out week after week is something to be cherished.

Jesus and Mo is not, however, simply a work of courage. It is also illuminating and witty, sophisticated and challenging. The cartoons are based on a simple format (Jesus and Mohammed sharing a house, discussing religion, politics and philosophy, between themselves and, occasionally down the pub with an atheist barmaid) and limited to four frames. But beneath the simplicity, brevity and humour lies often a rare depth and seriousness.

One of my favourite cartoons shows Jesus and Mo explaining to the barmaid the Aristotelian idea, later picked up by both Islamic and Christian theologians, that ‘Everything that has a beginning must have a cause’ and ‘the universe has a beginning, therefore it must have a cause’. ‘Therefore?’, asks the barmaid. ‘Therefore no bacon’, replies Mo. ‘Or gay sex’, chips in Jesus. It is a typical dig at the illogicalities of religious faith. It also, in Jesus and Mo’s inimitable way, taps into one of the most difficult theological conundrums for believers, the tension between the idea of God as ‘first cause’, or as a ‘condition of being’, and the God of scriptures that does all the other things that religion requires of Him: perform miracles, answer our prayers, wrestle with the devil, set down moral law, punish sinners. And tell us to keep off the bacon sarnies and gay sex. I give an hour-long lecture on this topic. Jesus and Mo get to the heart of the matter in four frames.

Nor is it just religion that Jesus and Mo cartoons dissect. They unpick many of the idiocies of liberal culture too. Another of my favourite cartoons shows Jesus and Mo sitting at the bar having ‘pledged not to say anything that might cause one of them to feel offended.’ They sit in silence. And still more silence. Until finally Mo says, ‘This is nice, isn’t it’. In one cartoon strip, getting to the fundamental problem with the liberal fear of giving offence.

The humour in Jesus and Mo is not brash or vicious as in Charlie Hebdo. It is gentle, but also gently subversive, respectful even, but also respectfully challenging. It is easy to see why many would dislike, even despise it. It is more difficult to imagine why anyone should find it offensive in any meaningful sense. Yet, many do just that, and not just hardline believers.

Last year, a controversy erupted in Britain when Maajid Nawaz, once an Islamist, now a leading figure in the Quilliam Foundation, a London-based counter-extremism organization, tweeted that he was not offended by Jesus and Mo cartoons. ‘I’m sure God is greater than to feel threatened by it’, he observed. At which point all hell broke loose. Other Muslim activists organized an international campaign of vilification. Nawaz received a torrent of abuse on social media and a sackful of death threats. There was something truly bizarre (and yet in keeping with the zeitgeist of our age) that someone should become the focus of death threats for suggesting that an inoffensive cartoon was, well, inoffensive. There was also something in keeping with the zeitgeist in the response of many liberals.

Channel 4, one of Britain’s major broadcasters, and one prized for its liberal, open attitude to cultural issues, organized a debate around the controversy. The programme showed one of the cartoons – but blanked out Muhammad’s face (and only Muhammad’s face). In the context of a debate about whether Nawaz had been right to tweet the cartoon in the first place, or whether his critics were right to hound him for ‘offending’ Muslims, it was an extraordinary decision. The broadcaster had effectively taken sides in the debate – and taken the side of the reactionaries against the liberal.

Channel 4’s actions may have been indefensible, but they were also sadly typical. The reactionaries may be reactionary, but what gives them room to operate is the pusillanimity of many so-called liberals, their unwillingness to stand up for basic liberal principles, their fear of causing offence.

In a world defined by outrage and offence and liberal spinelessness, Jesus and Mo is a treasure, whose value we should never fail to recognize. Read them. Laugh. And think.