Moderate believers argue that Isis has misinterpreted the Koran. But no one can determine who is right or wrong, argues Matthew Syed.

Who are the real Muslims? Who are the bona fide, authentic, true-to-the-core followers of the Islamic faith? Now, that might seem like an easy question. Surely, the people who are Muslims are those who say, when asked: "I am a Muslim."

But there is a problem with this approach. As you may have noticed, Sunnis, many of them, tell us that they are the real Muslims and that the Shias are impostors. The Shias tell us the exact opposite. The Sufis have a quite different perspective: they reckon that both the Sunni and Shia brigades have it wrong, and that they have it right.

Some Muslims are pretty ecumenical. There are moderate Muslim groups in the UK who say that Islam is a broad church. They say they don't really have a problem with Sunni or Shia. But guess what? They don't extend this embrace to Islamic State (Isis). They describe its approach as "a perversion of Islam".

Barack Obama and Tony Blair have it in for Isis, too. Blair said that Isis possesses "an ideology that distorts and warps Islam's true message" while Obama went even further, saying: "[Isis] is not Islamic. No religion condones the killing of innocents, and the vast majority of [its] victims have been Muslim . . . [it] is a terrorist organisation, pure and simple."

But what is their evidence for this? Members of Isis say that they are real Muslims. They say that they are inspired by the Koran. They say that they are killing and maiming people because that is what Allah wants them to do. They talk about their love of God and the glories of martyrdom. I reckon that, if we are going to take other Muslims at their word, we should take members of Isis at their word, too.

You see, the idea of "real" and "false" Muslims is ephemeral. With something like science, people who disagree with each other examine the evidence. They debate, they argue, they perform experiments. Sadly, this approach is not available for religious disputes. People with theological differences tend to appeal to divine revelation and differing interpretations of manuscripts that were written centuries ago. This is a problem when it comes to resolving differences, particularly when those manuscripts contain passages that seem, on a cursory reading, to condone violence.

It is no good Blair or Obama, or anyone else, saying that Isis has got it wrong, or that it is distorting Islam's "true message" because, when it comes to religious truth, there is no such thing as "wrong" — unless, of course, you happen to be the one person, one group, one faction, that is wired up to God. And think of the hypocrisy, too. Blair is a Catholic. He doesn't believe in Allah (unless he is the same as Jehovah/Yahweh/the God of Moses). Nevertheless, he feels entitled to rule on the question of who are Allah's chosen people. In other words, he is happy to second guess the views of a deity he thinks is fictional.

Other western politicians are engaged in the same duplicitous charade, as the philosopher Daniel Dennett has noted.

Senator Rand Paul, of Kentucky said: "I think it is important not only to the American public but for the world and the Islamic world to point out this is not a true form of Islam".

David Cameron and Ed Miliband have also jumped on the bandwagon, claiming that jihadists are motivated, not by Allah, but by hatred. This is surely untrue. To a man, the jihadists say they are motivated by faith.

Instead of pontificating on who are the real Muslims, isn't it time to acknowledge that the entire debate

is senseless?

Moderate Muslims would not like such a stance, of course. They would hate to be told that their interpretation of Islam is no more legitimate than that of Isis. But the alternative is far worse because it perpetuates the idea that there is a rational means of figuring out which of the subgroups has a hotline to God.

This takes us to the elephant in the room. The fundamental problem in the Middle East today is not with the Sunni or the Shia or even with Isis. The problem is with religion itself. It is the idea of received wisdom, divine revelation, the notion that "I have heard the Truth" and that everyone else is deluded. This is the corrupting, anti-rational, distorting engine of religious violence in the Middle East, just as it once triggered Christianity into a bloody civil war.

Truth divorced from evidence (or anything that counts as evidence) is perilous. Religion is not the only cause of violence, of course, but it has a particular virulence.

Members of my family have argued for jihad, not because they are crazy or unsympathetic, but because they think this is the will of God. They think this because the Koran, a bit like the Bible, has elements that can (rather easily) be interpreted as authorising violence.

Christianity has improved its record on violence in recent centuries, but only because it has become less religious. The farther it has retreated from the idea of revealed truth, the less it has killed people who take a different view. Most Christians today associate truth with evidence, reason and other Enlightenment ideals.

For all the debate over foreign policy, this is the only solution to the bloodshed in the Middle East, too.

Matthew Syed is a columnist and feature writer for The Times. This article first appeared in the Times (£) and is reproduced here with the author's permission. The views expressed in this article are those of the author and do not necessarily represent those of the NSS.