Writing biography is a strange thing to do. It's a journey into the foreign territory of somebody else's life, a journey, an exploration that can take you places you never dreamed of going and still can't quite believe you've been, especially if, like me, you're an agnostic Jew and the life you've been exploring is that of Muhammad. Five years ago, for instance, I found myself waking each morning in misty Seattle to what I knew was an impossible question: What actually happened one desert night, half the world and almost half of history away? What happened, that is, on the night in the year 610 when Muhammad received the first revelation of the Koran on a mountain just outside Mecca? This is the core mystical moment of Islam, and as such, of course, it defies empirical analysis. Yet the question wouldn't let go of me. I was fully aware that for someone as secular as I am, just asking it could be seen as pure chutzpah. (Laughter) And I plead guilty as charged, because all exploration, physical or intellectual, is inevitably in some sense an act of transgression, of crossing boundaries. Still, some boundaries are larger than others. So a human encountering the divine, as Muslims believe Muhammad did, to the rationalist, this is a matter not of fact but of wishful fiction, and like all of us, I like to think of myself as rational. Which might be why when I looked at the earliest accounts we have of that night, what struck me even more than what happened was what did not happen. Muhammad did not come floating off the mountain as though walking on air. He did not run down shouting, "Hallelujah!" and "Bless the Lord!" He did not radiate light and joy. There were no choirs of angels, no music of the spheres, no elation, no ecstasy, no golden aura surrounding him, no sense of an absolute, fore-ordained role as the messenger of God. That is, he did none of the things that might make it easy to cry foul, to put down the whole story as a pious fable. Quite the contrary. In his own reported words, he was convinced at first that what had happened couldn't have been real. At best, he thought, it had to have been a hallucination -- a trick of the eye or the ear, perhaps, or his own mind working against him. At worst, possession -- that he'd been seized by an evil jinn, a spirit out to deceive him, even to crush the life out of him. In fact, he was so sure that he could only be majnun, possessed by a jinn, that when he found himself still alive, his first impulse was to finish the job himself, to leap off the highest cliff and escape the terror of what he'd experienced by putting an end to all experience. So the man who fled down the mountain that night trembled not with joy but with a stark, primordial fear. He was overwhelmed not with conviction, but by doubt. And that panicked disorientation, that sundering of everything familiar, that daunting awareness of something beyond human comprehension, can only be called a terrible awe. This might be somewhat difficult to grasp now that we use the word "awesome" to describe a new app or a viral video. With the exception perhaps of a massive earthquake, we're protected from real awe. We close the doors and hunker down, convinced that we're in control, or, at least, hoping for control. We do our best to ignore the fact that we don't always have it, and that not everything can be explained. Yet whether you're a rationalist or a mystic, whether you think the words Muhammad heard that night came from inside himself or from outside, what's clear is that he did experience them, and that he did so with a force that would shatter his sense of himself and his world and transform this otherwise modest man into a radical advocate for social and economic justice. Fear was the only sane response, the only human response. Too human for some, like conservative Muslim theologians who maintain that the account of his wanting to kill himself shouldn't even be mentioned, despite the fact that it's in the earliest Islamic biographies. They insist that he never doubted for even a single moment, let alone despaired. Demanding perfection, they refuse to tolerate human imperfection. Yet what, exactly, is imperfect about doubt? As I read those early accounts, I realized it was precisely Muhammad's doubt that brought him alive for me, that allowed me to begin to see him in full, to accord him the integrity of reality. And the more I thought about it, the more it made sense that he doubted, because doubt is essential to faith. If this seems a startling idea at first, consider that doubt, as Graham Greene once put it, is the heart of the matter. Abolish all doubt, and what's left is not faith, but absolute, heartless conviction. You're certain that you possess the Truth -- inevitably offered with an implied uppercase T -- and this certainty quickly devolves into dogmatism and righteousness, by which I mean a demonstrative, overweening pride in being so very right, in short, the arrogance of fundamentalism. It has to be one of the multiple ironies of history that a favorite expletive of Muslim fundamentalists is the same one once used by the Christian fundamentalists known as Crusaders: "infidel," from the Latin for "faithless." Doubly ironic, in this case, because their absolutism is in fact the opposite of faith. In effect, they are the infidels. Like fundamentalists of all religious stripes, they have no questions, only answers. They found the perfect antidote to thought and the ideal refuge of the hard demands of real faith. They don't have to struggle for it like Jacob wrestling through the night with the angel, or like Jesus in his 40 days and nights in the wilderness, or like Muhammad, not only that night on the mountain, but throughout his years as a prophet, with the Koran constantly urging him not to despair, and condemning those who most loudly proclaim that they know everything there is to know and that they and they alone are right. And yet we, the vast and still far too silent majority, have ceded the public arena to this extremist minority. We've allowed Judaism to be claimed by violently messianic West Bank settlers, Christianity by homophobic hypocrites and misogynistic bigots, Islam by suicide bombers. And we've allowed ourselves to be blinded to the fact that no matter whether they claim to be Christians, Jews or Muslims, militant extremists are none of the above. They're a cult all their own, blood brothers steeped in other people's blood. This isn't faith. It's fanaticism, and we have to stop confusing the two. We have to recognize that real faith has no easy answers. It's difficult and stubborn. It involves an ongoing struggle, a continual questioning of what we think we know, a wrestling with issues and ideas. It goes hand in hand with doubt, in a never-ending conversation with it, and sometimes in conscious defiance of it. And this conscious defiance is why I, as an agnostic, can still have faith. I have faith, for instance, that peace in the Middle East is possible despite the ever-accumulating mass of evidence to the contrary. I'm not convinced of this. I can hardly say I believe it. I can only have faith in it, commit myself, that is, to the idea of it, and I do this precisely because of the temptation to throw up my hands in resignation and retreat into silence. Because despair is self-fulfilling. If we call something impossible, we act in such a way that we make it so. And I, for one, refuse to live that way. In fact, most of us do, whether we're atheist or theist or anywhere in between or beyond, for that matter, what drives us is that, despite our doubts and even because of our doubts, we reject the nihilism of despair. We insist on faith in the future and in each other. Call this naive if you like. Call it impossibly idealistic if you must. But one thing is sure: Call it human. Could Muhammad have so radically changed his world without such faith, without the refusal to cede to the arrogance of closed-minded certainty? I think not. After keeping company with him as a writer for the past five years, I can't see that he'd be anything but utterly outraged at the militant fundamentalists who claim to speak and act in his name in the Middle East and elsewhere today. He'd be appalled at the repression of half the population because of their gender. He'd be torn apart by the bitter divisiveness of sectarianism. He'd call out terrorism for what it is, not only criminal but an obscene travesty of everything he believed in and struggled for. He'd say what the Koran says: Anyone who takes a life takes the life of all humanity. Anyone who saves a life, saves the life of all humanity. And he'd commit himself fully to the hard and thorny process of making peace. Thank you. (Applause) Thank you. (Applause)