On Tuesday morning, an 85-year-old man was forced to his knees while his throat was slit by Islamic fanatics. The murder of Father Jacques Hamel in the church at Saint-Étienne-du-Rouvray, near Rouen, has been recognised by western public opinion as an act of unspeakable barbarity. One could say that the facts speak for themselves. But for Catholics, this atrocity possesses a special horror.

Father Hamel was killed while re-enacting the death of Jesus Christ on the cross. That is the essence of the Catholic Mass, which — unlike Protestant commemorations of the Last Supper — is presented to the faithful as the same sacrifice offered by Jesus.

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To kill a priest who is saying Mass is therefore an act of unique desecration. You do not need to be a believer to grasp this point. Enemies of the church have understood it since the beginning: an early pope, St Sixtus, was beheaded during Mass in 258 ad by agents of the Emperor Valerian.

Islamists, who reach back to the Dark Ages for so many of their actions, have rediscovered this crime. Their intense (and very successful) campaign to cleanse the Middle East of Christians reached its symbolic peak on 31 October 2010, when Father Thaer Abdal was shot dead at the altar of the Syrian Catholic church of Our Lady of Salvation in Baghdad. Fifty-seven other innocent people, many of them worshippers, died with him.

The gunmen who broke into the church during Sunday Mass were heard to scream: ‘All of you are infidels… we will go to paradise if we kill you and you will go to hell.’ They were members of an Iraqi faction of al-Qaeda that had declared war on churches, ‘dirty dens of idolatry’, and in particular ‘the hallucinating tyrant of the Vatican’.

The motives of Islamic terrorists are sometimes hard to disentangle from their personal biographies and factional infighting. But sometimes they are obvious, and the only thing obscuring them is the politically correct preciousness of the liberal western media and commentariat.

Many Islamic fundamentalists, including those who don’t participate directly in violence, loathe Christianity with a poisonous passion reminiscent of medieval Christian anti-Semitism. Its practice must be suppressed — either without violence, as in Saudi Arabia, or amid carefully staged scenes of bloodshed, as in Baghdad or Rouen.

In the 21st-century Middle East, Christianity has been suppressed on an astonishing scale. Countless atrocities have reduced ancient Christian communities to shrivelled and terrified ghettoes or underground churches. Although this persecution has been reported in the West, it is of no great interest to secular politicians or the media. It is, as Neville Chamberlain said in a different context, part of ‘a quarrel in a faraway country between people of whom we know nothing’.

On Tuesday, the blood of a martyr was spilled at the other end of the Channel Tunnel. Now Christians in the West have had a glimpse of what it’s like to be a follower of Jesus in the lands of the Bible and many other countries — not all of them Muslim, but a troubling number of them ‘close allies’ who benefit from British trade deals, foreign aid and general diplomatic brown-nosing.

Will the murder of Father Hamel awake Christendom from its torpor? Let me refer you to the Twitter account of one Dr Austen Ivereigh, hagiographer of Pope Francis and former spokesman for the English Catholic Church. He referred to the ‘pointless banality of the Rouen murder’ and urged us not to glorify it by ‘ascribing religious motives’. There’s your answer.