Jeanette Winerson on the consoling power of poetry as a TS Eliot festival opens in London

Language is what stops the heart exploding. Or as TS Eliot puts it in Murder in the Cathedral, "This is one moment / But know that another / shall pierce you with a sudden painful joy."

When I was growing up poor and Pentecostal in the north of England, books were not allowed in our house, unless they were Bible books or my mother's mystery stories - not of the miracle play kind, but of the Agatha Christie and Ellery Queen kind. My mother made the rules as violently and as eccentrically as any tinpot despot, and my counter-strategies included smuggling books into the house and hiding them under the mattress, or reading them in the public library. Fatefully, when I was 16, and just as she was about to throw me out of the house for ever, for breaking a very big rule (not just No Sex, but definitely No Sex With Your Own Sex), my mother made a mistake. She sent me to the library to collect her weekly haul of mysteries - and on her list was Murder in the Cathedral.

She thought it was a saga of homicidal monks. In the library, I opened it - it looked a bit short for a mystery story. I hadn't heard of TS Eliot, but I read the line about "sudden painful joy" and I started to cry. Readers looked up reproachfully, and the librarian reprimanded me, because in those days you weren't even allowed to sneeze in a library, and so I took the book outside and read it all the way through, sitting on the steps in the usual northern gale.

The unfamiliar and beautiful play made things bearable that day, and the things it made bearable were another failed family (I am adopted, so being packed off for a second time was very hard), the confusion of sexuality, and the straightforward practical problems of where to live, what to eat and how to get on with my A-levels.

So when people say that poetry is merely a luxury for the educated middle classes, or that it shouldn't be read much at school because it is irrelevant, or any of the strange and stupid things that are said about poetry and its place in our lives, I suspect that the people doing the saying have had things pretty easy. A tough life needs a tough language - and that is what poetry is. That is what literature offers - a language powerful enough to say how it is.

Let's not confuse this with realism. The power does not lie directly with the choice of subject or its social relevance - if it did, then everything not about our own contemporary situation would be academic to us, and all the art of the past would be a mental museum. Art lasts because it gives us a language for our inner reality, and that is not a private hieroglyph; it is a connection across time to all those others who have suffered and failed, found happiness, lost it, faced death, ruin, struggled, survived, known the night-hours of inconsolable pain.

Eliot says: "Humankind cannot bear very much reality." That, for him, was not the reality of dingy streets and gas fires, typists and tinned food, though he writes about those things so well, but the vast reality of two quite different invisible worlds - "the heavy burden of the growing soul" (Animula), and what might be called the "shaft of sunlight" (Four Quartets), a spiritual illumination that became, for Eliot, a journey towards God.

For Eliot, the 3D world where we live, that which he calls in The Waste Land the "unreal city", is a beguiling or distressing distraction from facing life head on, facing ourselves as we are - and ultimately, facing God. He is tough, he refuses consolation, "Time is no healer: the patient is no longer here."

When I read him that day, gales battering me within and without, I didn't want consolation; I wanted expression. I wanted to find the place where I was hurt, to locate it exactly, and to give it a mouth. Pain is very often a maimed creature without a mouth. Through the agency of the poem that is powerful enough to clarifying feelings into facts, I am no longer dumb, not speechless, not lost. Language is a finding place, not a hiding place.

The Waste Land (1922), Eliot's most read and best-known poem, is stark enough - no place to hide there - but it is a poem that finds a language for the wholly new situation in the aftermath of the first world war. The genius of The Waste Land as a defining poem is just what it defines: yes, the old 19th-century certainties of progress, of industry, of advancement of civilisation, of the very idea of civilisation, are in ruins, but Eliot understood too that the first world war had devastated consciousness - the inside of people's heads, as well as their world order. Linear narrative no longer makes sense - and so poets, and poet-novelists, can no longer write in that way.

Virginia Woolf moved towards this new understanding in Jacob's Room, and Joyce violently displayed it in Ulysses, both fictions (I can't call them novels in the 19th-century sense of the word) also published in 1922. The Waste Land is really a collection of poems, an assembling of poetic forms, and voices, moving in different directions simultaneously. It bursts out of any recognisable poetic shape just as the world had burst out of any recognisable order.

There are critics - Denis Donoghue is one - who don't like The Waste Land being described in grand terms as a poem "about" the fall of western civilisation. It's true that Eliot did not like his poems being "about" things, and it's true too, as Susan Sontag puts it, that a work of art is not just "about" something, it is something.

Eliot composed in fragments, often waiting for some catalyst to help him shape his fragments into a total work, and some of The Waste Land was written early, in response to the breakdown of his first marriage, circulating round his wife Vivienne's madness. There seems to me to be a connection between private and public breakdowns, and I believe that creative people act as antennae, feeling what is coming long before it does - rather as animals sense an earthquake or a tsunami.

The Waste Land intuitively understands what will become the century of ceaseless movement - of peoples, of information, of goods, of ideas, a flow that becomes a flood, where nothing, finally, seems to be in the right place, where nothing is held, where the positive energy of free markets and unrestricted access, of democracy, of travel, of opportunity, gives way to flux without purpose, agitation, instability: "The loitering heirs of City directors; Departed, have left no addresses."

The mobile/Blackberry generation. The migrant workers. Metropolitan police pensions in Iceland. All this is in the restlessness of The Waste Land, pre-figured, understood, in the "heap of broken images" that is our world.

But poets are not here to do the job of historians or docu-dramatists. It is the emotional state of the situation that poetry can enter. When Eliot says, in Four Quartets,"We had the experience but missed the meaning", he is closing in on the problem of modern life - too fast, too surface, void of the emotional understanding that balances our dependence on practical reality and rational thought. We need our emotions as a navigation towards meaning, and that is what poetry allows.

Eliot has a reputation for being cold-blooded, analytical, remote. We don't think about him as we do Robert Graves or Ted Hughes, certainly not as we do Keats or Byron, with their wild cries and sensuous passions. Eliot himself liked to talk about "impersonality" as a necessary virtue in a poet, but we should not misunderstand him. In his 1927 essay "Shakespeare and the Stoicism of Seneca", he muses on Shakespeare's "struggle to transmute his personal and private agonies into something rich and strange, universal and impersonal".

In the land of reality TV and confessional talk shows, Eliot's wish to withdraw the personal from his poetry - from any poetry - is easy to misread. But the paradox of the best writing is that while the writer's voice is unmistakable, the writer has somehow performed the Indian rope trick and disappeared. Celebrity culture can't imagine anyone wanting to disappear, or that such a thing might be necessary. Now, when we are told that everything depends on our "personality", it seems strange to hear Eliot saying, as he does in his essay "Tradition and the Individual Talent", that "poetry is not a turning loose of emotion, but an escape from emotion; it is not the expression of personality, but an escape from personality. But of course only those who have personality and emotions know what it means to want to escape from those things."

His conversion to Anglicanism and his increasing religious conviction are a stumbling block for many people coming to his poetry. Religion is unfashionable, and Eliot is thus viewed as untrustworthy. I suspect that the religious question is often a convenient way out of grappling with the difficulty of the poetry. Denis Donoghue, a critic I admire, even when I am disagreeing with him, sensibly refutes the religious hoo-ha when he says, "it should not be impossible for readers to imagine certain convictions that they don't otherwise feel". Eliot's supposed antisemitism is an even bigger problem for some readers. Reams have been written about it, just as with Wagner, the conclusion being, I think, that such an ugly prejudice must fatally weaken the work. But it's not the case that flaws in the human being necessarily weaken or infect the work. If that were so, given the lives, tensions, contradictions, murderous intent, wife-battering, drug taking, suicidal mania and dangerous affiliations of many of our great artists, there would be little work left of any value. I do not find Eliot guilty as charged of antisemitism; he was not his friend Ezra Pound, though even Pound, at the end of his life, movingly apologised to Allen Ginsberg. Just as movingly, the Jewish Ginsberg still revered the fascist writer, forgave him even, because he recognised the value of Pound's work, poet to poet. Whether or not my view of Eliot's antisemitism is the correct one, the work is splendid.

I said earlier that poetry finds a language for our inner reality; it does, but the "shafts of sunlight" Eliot understands are intimations of . . . well, he would say God, and I can't, quite, but I can say something nearly as bad for Dawkins-types, such as the kick of joy in the universe. There's more to it, anyway, than our own small realities, inside and out. It used to be called the Sublime.

Eliot's poetry finds the right balance between the sacred and the secular, and it is good that an artist, any artist, should be unafraid of spiritual realities. Eliot's plays suffer, though, from religious overload, and they are not entirely successful as drama, though I suspect their awkwardness is a failure of form and not an excess of religious sensibility. Simply, form and content are not perfectly merged, as they are in the poetry. Eliot knew this, and talks about it frankly in a number of essays. He wanted to experiment with verse-drama, and he was bored with what he called "Shaftesbury Avenue farces" on the one hand, and on the other, serious, but in his view, trivial, prose-plays on some passing hot topic.

For all Eliot's impatience with "meaning" as a kind of stick-on label, and his severity towards those who were endlessly "interpreting" his work, he was a writer who wanted to influence and change his milieu. He was an admirer of George Bernard Shaw, and particularly of St Joan because it wasn't tied to the present day. It was an influence on Murder in the Cathedral.

The Family Reunion is Eliot's second attempt at verse-drama; less beautiful than Murder in the Cathedral, but fiercer in its focus. When Harry comes home for his mother's birthday, he finds that there are unexpected surprises waiting for him. The fear, confession, and something like redemption that follow are saved from melodrama by the tightness of the language, but still the play is part failure, part success. Eliot was worried that the Furies - his Chorus device - would look like ghosts if they were inside the room, and shrubbery if they were placed in the garden. It will be interesting to see how the production at the Donmar gets round this, and whether or not the play - as a play, and not as poetry plus action - can be made to work. Clunky though it is, its intensity is like sitting under a hot lamp.

To put Eliot's poetry and plays in a dramatic context is to position him favourably for an audience who may not be sure about his work. Poetry begins in the mouth before it reaches the page: it is an oral art, but these days children don't learn poetry by heart, and adults read it quietly, if at all. What poetry isn't, is an academic exercise. I read Eliot by pacing up and down to get the rhythm right, and I suspect that anyone hearing him out loud for the first time will be surprised, and excited, at the force and pace of the poetry. I still find myself back on the library steps, calm but not tranquilised, freed from my own overwhelming emotion by the poet's contained emotion.