On Monday evening a service of remembrance was held in Arras cathedral in northern France. The congregation was there to pay its respects to Dominique Bernard, the teacher who was murdered by an Islamist at his school last Friday, not far from the cathedral. The service was led by Bishop Olivier Leborgne. ‘We don’t have all the answers, but we believe that peace is our future,’ he told the congregation. As worshippers lit candles, the choir sang ‘Jesus, the Christ, the inner light, don’t let the darkness speak to me’.

The Libyan who knifed to death three gay men in a park in Reading didn’t have much fraternal feeling, nor did the Tunisian who shot dead two Swedes

At around the same time as Bishop Leborgne and his congregation prayed for peace, 100 miles east a man opened fire with a semi-automatic rifle on a group of Swedes in Brussels. Abdesalem Lassoued, who was shot dead by Belgian police on Tuesday morning, was a 45-year-old Tunisian failed asylum seeker who was living in Belgium illegally. In his homeland, he was known to the authorities as an Islamic extremist.

Shortly after he had killed two Swedes and gravely wounded a third, Lassoued posted a justification on social media. ‘I am a fighter for Allah,’ he said. ‘I am from the Islamic State. We love who loves us and we hate who hates us. We live for our religion and we die for our religion.’ Among the congregation in Arras cathedral was the director of the city’s main mosque. ‘Whoever did this unimaginable act is not a human being to us,’ he said, referring to the man who has been charged with killing Dominique Bernard. ‘This person obeys no law, no religion’.

That’s not how the Islamist terrorists see it. In their minds they are obeying their religion in killing the infidel; it may not be the Islam followed by the director of the Arras mosque and millions of other Muslims who denounce and reject violence carried out in the name of their religion. Nonetheless, many other Muslims are ready to kill: not just Catholics and Jews, but their fellow Muslims. Thirty of the 86 people murdered by a Tunisian Islamist in July 2016 in Nice were Muslims.

The director of the mosque in Arras is well-intentioned but naive, a description that is also true of his host on Monday evening, Bishop Leborgne. For several years he has been a fervent champion of migrants, making frequent visits to the makeshift camps at Calais to offer his support to those people hoping to reach England. Last year he published a book – Pray for the Present Time – in which he asked for compassion for migrants, and in a recent interview he likened today’s migrants to Mary and Joseph, who were forced into exile in Egypt after the birth of the baby Jesus.

Bishop Leborgne was appointed to his position by the Pope, whose indulgence of illegal immigration is well known. Last month in Marseille the Pontiff urged Europe to be more welcoming to migrants because ‘those who take refuge in our midst should not be viewed as a heavy burden to be borne: if we consider them instead as brothers and sisters, they will appear to us above all as gifts.’

A question that doesn’t appear to have crossed the mind of the Pope is what if some of these newcomers don’t regard Europeans as ‘brothers and sisters’, but rather as the enemy, either because of religion or sexuality. The Libyan who knifed to death three gay men in a park in Reading didn’t have much fraternal feeling, nor did the Tunisian who shot dead two Swedes. The man who carried out the attack in the Arras school recorded a message prior to his act in which he pledged allegiance to the Islamic State and expressed his hatred ‘of the French, democracy and the education he had received’.

As I wrote in June, such incidents are not isolated; they are becoming frequent. Almost one year ago to the day, Bishop Leborgne officiated at the funeral of 12-year-old Lola, the Parisian girl raped and murdered, allegedly by an Algerian woman who was in France illegally.

Like the woman accused of murdering Lola, the man charged with the murder of schoolteacher Dominique Bernard should not have been in France. An attempt was first made to expel the radicalised family – who sought refuge in France from the Caucasus in 2008 – in 2014. An aircraft was ready to fly the family back to southern Russia but the Communist party, aided by several human rights organisations, intervened to stop the deportation. The Communists issued a press statement praising the team effort ‘that succeeded in getting the prefecture to back down… what a waste of resources to sabotage a family’s life!’

Although the father was subsequently expelled, the rest of the family were given leave to remain; one son is serving five years in prison after being convicted earlier this year of plotting to attack the Elysee Palace, another is accused of murdering a schoolteacher and a third, aged 16, is charged with complicity in the crime that has genuinely sabotaged a family’s life, leaving a wife to grieve her husband and three daughters their father.

There have now been two Islamist attacks in four days in Western Europe, and there will surely be more in the weeks and months ahead. According to reports in Wednesday’s newspapers, demonstrators in the Arab world have been chanting ‘death to England and France’.

Following the murderous attack on his nationals, Sweden’s Prime Minister Ulf Kristersson demanded greater border controls because Europe could no longer afford to ‘naive’ in the face of the terrorist threat. A few French politicians said something similar in June, after a Syrian who had been refused asylum in Sweden came to France and stabbed several babies and toddlers in a playground in Annecy. Those calls were ignored by Europe’s leaders, and it would be a surprise if anyone listens to Mr Kristersson.

The EU believes like Bishop Leborgne that ‘peace is our future’. It hasn’t the intellectual bandwidth to comprehend a world of war and religious conflict. If such a conflict is to come, it won’t be won with candles and prayers. Victory will be secured with resolve and realism, what some French commentators on the right call ‘ideological rearmament’. A good starting point would be the acceptance that not everyone comes to Europe with peace in their heart.