I have been studying and thinking about Islam for almost half my life. I got a slight head start on much of the rest of the world thanks to a Sufi Muslim friend. From her I learned, in those pre-9/11 days, about the horrors of the Wahhabis and the Salafis, the Deobandis and the Khomeinists. And I heard about one thing in particular which I have since observed: how moderate movements in Islam have repeatedly lost out to the hardliners and how some of the most enlightened people you might meet can be trampled over by the most barbaric. It was a timely lesson. In the struggle for an enlightened form of Islam one can find many Muslim allies. But their organised history is one of repeated failure.

Confronting hatred: The author (grey suit, left) and Islamist preacher Anjem Choudary (centre) clash outside a debate in 2009

If the discussion about the future of Islam once used to be confined to an exotic theology, it no longer is. The future of Islam and the future of the West are now inextricably linked. If disentangling them was ever possible it is almost certainly not now. What happens to Islam will affect what happens to Europe.

Before travelling over some of the possible paths it is worth remembering one key fact — as Bernard Lewis among others has said — there are essentially three Islams. There is the Islam of the Koran, Hadith and life of Muhammad. Then there is the extrapolation of this into the system of law known as sharia. And then there is a third Islam — Muslims themselves, what they do and how they live.

Even the briefest period spent studying the first two Islams should lead anyone — especially anyone brought up in another religion, let alone none at all — to worry. The traditions and the foundations on which the religion of Islam is built are deeply troubling — filled with imprecations to violence, oppression and conquest. Sharia, built upon these foundations, is a system of rules which would make any modern citizen shudder. It is very hard to see how this system of laws can be reformed in a way that remains true to their sources without going so far away from them as to cause the centrality of those sources to crumble. These are serious and profound negatives, to which I will return. But they are balanced by one very significant positive which must always be borne in mind: what Muslims actually do.

Anybody living in a Western society who troubles over Islams One and Two may find Islam Three to be slightly baffling at first. Later they should find it a considerable relief, because although an undoubtedly large number of people exist who would wish to follow the violent and supremacist demands of Islams One and Two, a far larger proportion —indeed, as is often but necessarily said, the vast majority — do no such thing. They do not chop people's heads off or "slay the infidels wherever they find them". They just get on with their lives like the rest of us. They are parents and children, doctors and neighbours, chiropodists and friends. They are people who live with the inheritance of Islam One and Two lingering to various extents in the background of their everyday lives, and upon the memory of this tradition they build their family lives, weeks, calendars and some or a lot of their moral outlook. In other words, Islam Three is all around us. It is also Islam's — and our — only hope.