What happened during the first Easter in Jerusalem cannot be retrieved by the methods of historical inquiry. It is impossible to disprove the resurrection. But neither can the evidence of the Bible compel belief that something so clearly impossible happened. What can certainly be known are some of the stories told about the events of that weekend. These did change history, for better and for worse.

The worst is that the narrative in St John’s Gospel is the foundational document for modern antisemitism. Until that was written, the Jews were nothing special to their neighbours; but in that narrative they are clearly and deliberately responsible for the murder of the son of God – in some perspectives, the greatest crime that could ever be committed. The author of St John’s Gospel is traditionally identified with “the disciple whom Jesus loved”, but he must bear some responsibility for the subsequent persecution of hundreds of thousands of innocent people.

It is a legacy that is hard to shake off but it is not the only, or even the main, legacy of the story. Read from another perspective, the narrative has given strength to millions of Christians to endure every kind of persecution and injustice, and to try even in the midst of that to return only good for evil. More than that, it has seeped into the consciousness of half-believers, of unheroic and unmartyred Christians and into everyone who believes in western ideals of progress.

It is because of the Easter story that we believe there is something wrong in the suffering of the weak, the friendless, and even of those who believe that God has forsaken them, as Jesus cried out that he had been from the cross. This would have seemed an absurdity to the Romans, the Greeks, or even the cultures celebrated in the stories of the Old Testament. Assyrians or Romans might not have had the Christian reasons for persecuting Jews, but they would slaughter them by the thousand for reasons of state. The casual cruelty of traditional empires cannot be overestimated. Whatever else the Romans gave us, it’s worth remembering for a moment the brutal horror of crucifixion. A method of public torture where it was considered a routine kindness to smash the legs of the dying victims so they would suffocate more quickly is hard to fathom, but it seemed to the Romans nothing more than common sense in the management of slaves.

The other point about this hideous cruelty is that it was effective. The Roman empire flourished for centuries. The argument of the high priest in the Gospel narrative, that it is expedient for one man to suffer for the sake of the people, is not specially evil. In fact, it is no more the recognition of one central social reality. It is one of the most realistic touches of the passion narrative that no one in it is egregiously wicked except perhaps Judas, and his motivation is nowhere fleshed out. The authorities, whether Jewish or Roman, are taking exactly the kind of hard decisions that are needed to preserve their power, and they are doing so in the belief that almost any order would be better than anarchy. None of them are saints, but neither are any of them doing any worse than a contemporary politician who decides it is expedient that African migrants should drown in the Mediterranean rather than disturb the balance of European societies – and as a result is re-elected by his grateful people.

Yet somehow from this ordinary exercise of necessary power, those who wrote the gospels and those who read them afterwards drew the absurd and entirely novel conclusion that the way of the world is radically wrong. Pilate might argue that by crucifying Jesus he prevented a revolution and ensured for the inhabitants of Jerusalem another 30 or 40 years of peace until their catastrophic revolt in AD66; but the Christian narrative has inserted into such reasoning a potent splinter of doubt. Necessity knows no law, said the Greeks, and on some level we all believe that. But we can also imagine – and sometimes seem to glimpse – a world where that was not true and in which all manner of things will be well. How to get there is another matter. It might be quite impossible without a miracle.

• This article was amended on 2 April 2018. An earlier version said that “the casual cruelty of traditional empires cannot be underestimated” where “overestimated” was meant.