Interview: The Rev Julie Nicholson

• The Rev Julie Nicholson, back left, with her husband Greg and children, left to right, Jenny, Lizzie and Thomas

A few months after her 24-year-old daughter Jenny was killed in the 7 July 2005 bombings, Julie Nicholson looked out the window of her study and saw a butterfly on the garden wall. She thought it was dying.

Nicholson is not a woman who worries unduly if she accidentally steps on a spider, but perhaps it was that combination of beauty and vulnerability that resonated so deeply. Gossamer wings, so easily torn from a fragile body. Whatever it was, rose up inside her in a kind of panic.

"I chased out into the garden and I was absolutely beside myself with grief that this butterfly was dying. I tried scooping it up. My other daughter, Lizzie, came in and said, 'What are you doing, Mum?' I said this butterfly… it's dying. 'It isn't,' said Lizzie. Then it flew away."

In her home in Bristol, Nicholson half laughs at the memory. "It had probably just been born and there was me pronouncing death. But it had that effect on me. Grief is a very strange country."

Nicholson has written a book, Song For Jenny, which examines intimately the terrain of that strange, hostile land: every exhausting hill and dangerous pothole, and conversely, every breathtaking viewpoint. A broken-down train on London's Bakerloo line meant Jenny was travelling on the wrong line, in the wrong direction, when she was killed by suicide bomber Mohammad Sidique Khan at Edgware Road.

At the time, Nicholson was vicar of St Aidan with St George church in Bristol, and her subsequent resignation attracted headlines. She was the vicar who couldn't forgive. The minister who lost her faith. It was not that simple.

Even before Jenny died, religion was not uncomplicated for Nicholson. (She wore red lacy underwear under her cassock the day she was ordained, a secret antidote to the more stultifying aspects of church institution.) Her background was working with young people in theatre projects and, before the bombings, she was already discussing how she could widen out her ministry from straightforward parish duties to include her love of theatre. She was always more creative than didactic.

"I was always consumed by doubts. I could never quite settle into answers and was always plagued by questions."

Once, after a church service, a member of the congregation spoke to her. "He said, 'You know, I am always more troubled than comforted by your sermons. You always have too many questions and I am looking for a few answers.' I really took that home with me. I nearly stopped doing the job that day." Then she realised something important. Certainty was a dead end. "It's only through doubts and questions that there is somewhere to progress to."

Nicholson has a special quality that is hard to define. She is tiny, describes herself as feisty but, to the stranger, the overwhelming sense is of stillness round her, of depth. Sudden bursts of warmth, laughter, mischief … yet underlying it all, a marked intensity.

As a priest, Nicholson met people destroyed by traumatic experiences. As a journalist, too, you get to recognise that tumour of hatred, of bitterness, that eats the inside of a person, leaving only their shell. But Nicholson has clearly not been destroyed. Looking at her, you wonder what divides people into those who are reshaped by tragedy and those who are simply misshapen by it. Is there actually a choice? Nicholson pauses for a long time. "I would need to think about that," she says finally.

You can intellectualise. Rationalise. But emotion is so visceral. Did she really choose, she ponders. "I knew instinctively and intellectually that I am not a bitter person, an unforgiving person. I don't think I have ever hated anybody in my life. But I was aware I could come to hate these people for what they did to Jenny and then I had to think, if I allow myself to become consumed by hatred, then it is a double tragedy – and what kind of model would that be for my remaining children?"

So she does not hate the bomber? "Well, hate is an odd word isn't it? I would have to understand that word a lot more but if you hate somebody, you wish them great ill, and he's dead. I am full of loathing for him, full of loathing, but I won't allow myself to talk about hatred."

In some ways, she feels no less a priest now than she ever did. Perhaps, one day, she will return. "But I had been rocked to the very core and I was in a healing ministry. I was too fragile to be working with people. I was just too hurt to carry out the functions of a parish priest. I could not have thought of conducting a funeral … I could not have stood in front of a young couple and married them without thinking, you should be my daughter … I could not have baptised a baby … and people deserve more than that."

It would, she admits, have been hard to use words of peace and reconciliation, but there were other, more practical, considerations. She said to a parishioner: "I can't get through an hour without crying." How could she get through the liturgy of the Eucharist? "People will understand," the parishioner said. Perhaps. "They may understand one week, or the next, but they might not understand if it went on week after week and actually, there are all sorts of people sitting in the congregation with their own hurts and traumas and I don't think they need their priest to be raising that to the surface all the time. So there was a bigger picture. Forgiveness was part of it but it wasn't the whole picture."

There was also something depressing about being part of an ailing institution. "Congregations are struggling to keep going, and there is quite a feeling of the thing dying, and I didn't feel I could be around more death."

That is not because she didn't face Jenny's death head on, but perhaps because she did. The police advised her not to look at photographs of her dead daughter. She insisted on looking at every last one. She was advised not to view Jenny's body. She insisted on that too. But what is striking is, despite being a minister, religion offered her almost no comfort in the aftermath of Jenny's death. She actively turned from it. "That is true," she admits. "I can't deny it. I wanted to be free, just to be the mother of my child. I didn't want the encumbrance."

There was one exception. She found the Pieta, the iconic religious image of the Madonna with the crucified body of Jesus on her lap, most famously captured in Michelangelo's sculpture, meant something powerful to her. And it was when she went to see her own child's broken body that she fell back on church ritual. Jenny was shrouded in muslin to soften the disfigurements caused by the bomb blast. Nicholson could hold only her cold hand, but she kissed every finger as she had when her daughter was born. Then she anointed her hand with oil and prayed. It is for that moment, Nicholson believes, that she was ever ordained a priest.

"I did not want to be defined by forgiveness or non-forgiveness," says Nicholson. We are sitting at her kitchen table where the light can still stream through in the early evening. She wanted to write about grief, about what it does to you. She wanted to record every minute of every day from 7 July, when Jenny went missing, to the identification of her body on 12 July, and her funeral a month later. "I had a need to write in great detail about those weeks, almost as if I had to relive it to believe it."

The result is a stunningly honest examination of grief, in which the reader is placed at the heart of Julie Nicholson's world, like a silent onlooker, as a cast of characters – her parents and sister, her nephews, nieces and cousins, her husband and children – move in and out of focus. At times, it is a brutal, uncomfortable world to be part of. When she describes her reaction to a survivor of the bombings, for example. At a day organised by the Metropolitan police, a distressed young woman came up to her in tears, apologising for surviving when Jenny did not. Nicholson describes in great detail her outward comforting of the girl, but her secret, inner repulsion at holding her in her arms.

She looks stricken when I raise it. "I wasn't going to write it at first," she admits. "She was the sweetest person. She was in such a distressed state and I had the instinctive level of wanting to comfort her and ease her distress, and yet I had this awful feeling that she wasn't who I needed her to be."

The description is uncompromising, just as it is when she describes sympathy cards whose sentiments sometimes irritated her. Nicholson is a woman who cares deeply about language. Jenny wanted her to be a novelist. But she gets frustrated by the inadequacy of words. After Jenny died, she feared she was losing her sense of beauty. Life felt over. The kindness and humanity of strangers helped over time but she wasn't always immediately able to respond to that. She records all her negative as well as positive responses, she says, because they show her limitations and nobody else's. This is the alien territory of bereavement and, if you have no map from those who have already walked it, it becomes even more terrifying. "I thought it very important to show how frightening it can be to have those feelings."

The world becomes unfamiliar. "I was surprised at myself, how at times I could be extremely composed in the most extreme circumstances, and then suddenly, for no apparent reason, I would turn into a monster."

Once, sitting alone, she hurled a bottle at the wall and watched the red wine splatter on books, papers and floor. "I would never believe that one day I would do that."

Another bereaved woman told Nicholson she went to her doctor because she kept forgetting things. "I thought, oh my goodness, I went to my doctor too, asking if grief could bring on early dementia. Even things like that can be really, really frightening."

When confronted by overwhelming emotions, most people instinctively try to keep a lid on them. They simply don't know how to deal with a person experiencing that kind of turmoil. Don't know what to say. So they resort to clich, even the non-religious grasping for rhetoric about God, heaven and angels. What other comfort is there? But Nicholson found she didn't actually want to be comforted. She wanted almost to embrace the pain. Sometimes, pain feels like all that's left. Once that goes, what live connection is there to the dead person?

For a while, says Nicholson, her surviving children, Lizzie and Thomas, lost their mother as well as their sister. Nicholson went to stay with her sister in Reading, where Jenny had lived with her boyfriend, James, while her husband stayed at home. "My connection was with Jenny in death more than it was with them in life and we have talked about that. Lizzie said for a while she would get so angry with me because I was putting more and more pictures of Jenny around the house. She said, 'Where are the pictures of me?' I said, 'Lizzie, this house is full of your art work.' But the sibling rivalry that is there in life does not go in death and that is a very important lesson."

It is also an important lesson that, when someone loved dies, the relationship becomes trapped in a kind of bubble of perfection, unsullied by everyday irritations and squabbles. Lizzie and Thomas felt the most loved child had died. Certainly, Jenny was vivacious and optimistic and had been a kind of soulmate for Nicholson in her love of music and literature. "But any parent will know that you have an abundance of love for your children and you love them – well I loved mine – equally but differently, because they are different people. What we had to do was reform our relationship without Jenny in the mix."

From the start, Nicholson and her husband, Greg, grieved very differently. She wanted to face the ugliness head on. Greg, perhaps, wanted to safeguard his memories of his lovely daughter. "I don't want to speak for him but I think he would say he wanted to keep Jenny in a place that was safe, and I think his grief was for his little first-born daughter." In the book, it is clear the marriage was in difficulty before Jenny died but Nicholson doesn't say what happens. Did it survive? "No," she says.

It wasn't Jenny's death that broke their relationship. "I was aware that for anyone reading the book there was a big question mark over where my husband was in my world at that time. I think we had acknowledged that separation might happen before all this and whatever happened, we wanted to retain a relationship as parents of our children. If there had really been anything to draw us back together, this would have done it. I think it showed us quite clearly, as the months went on, what was what."

Nicholson worked in a church theatre project after leaving her parish. Funding recently ran out and she experienced a few "dark nights of the soul" about her future. Then one morning she got up, feeling calm, knowing she was going to devote time to her book. She is still drawn to churches but listening to a sermon on forgiveness recently had a profound effect. It was a perfectly good sermon. A wonderful individual giving it. But the language alienated her. She realised she didn't need an institution to search for God.

Would she ever have preached that sermon before she lost Jenny? No. The shootings at Dunblane had made her careful about blanket forgiveness. "I think, deep down, I always felt that the one challenge that might be a challenge too far was if something awful happened to my child."

The tape is switched off. I'm about to leave when Nicholson says impulsively to stay for a drink. We sit in the kitchen talking as the light fades. Her future writing. Her son joining the marines. Life. It is then that one of the most truly horrible moments of my career happens. She asks about my children. I say laughingly, unthinkingly, that my eldest is so laid back he needs a bomb under him. It takes a second for the horror of what I have just said to penetrate. Only an expression? No. Ill-judged words are painful and this is a woman who wrestles with language. A woman who has grieved over the body of her child, shattered by a bomb.

aves of nausea. But I do what people do when faced with uncomfortable emotion. Keep the lid on. Pretend. If I don't acknowledge it, it didn't happen. She might not have noticed. Only an expression. I hear our voices but could not tell you what is said. It must be a full half-hour before I seize my chance. What I said earlier … such careless language ... I am so very sorry. She knows what I am referring to without the words being repeated. "It doesn't matter," she says, eyes flicking down. No, it does matter. She looks at me and says gently: "Well, I forgive you."

That moment brings something home. Earlier, Nicholson had said that the world couldn't function without forgiveness. Relationships couldn't function. Communities. But the word was used to cover everything from playground squabbles to genocide. "There are so many layers of meaning." Perhaps the important meaning is simply the absence of hatred. That is Nicholson's great achievement. Maybe asking more is inappropriate. "I really think," she says, "that it is not a mother's place to forgive the killer of her child."

The butterfly on the garden wall was not really dead. It was an illusion. Sometimes, Nicholson imagines what it would be like if reality could shift and Jenny be alive after all. If she could only twist life's kaleidoscope and have the random pieces fall in a different pattern. "Rarely a day goes by where I don't hope for her to walk through the door and for it all to have been a long, horrible nightmare. But I know that's not going to happen."

When Jenny disappeared, there was denial but underneath, there was something else. "I think, deep down, I had felt something sever. I don't know. It's a hard thing to put into words but I felt something go from me. I think from that moment I poured something of Jenny back into myself and when I am at my most positive, I like to think she is with me in everything that I do now."

The conventions of religion may have offered little comfort when Jenny died. But what about now, five years on? Is Jenny's death final? "In my heart she's not dead. She's very much alive in my heart and my memory." But alive in the sense that she will see her again? Nicholson hesitates. "There's nothing I would like more than to think that when I take my last breath on this earth, the first person I will see and embrace is Jenny. But I don't think it's quite that simple. I think it's more abstract and the truth of the matter is that I don't know. I will live the rest of my life wishing she were here, but understanding that she's not, and accepting that I can't know any more than that."

Yet there is one beautiful thing about uncertainty and that is the endlessness of its possibilities. "If I am proved wrong, and I go and there she is, then how wonderful a day that will be."

Song For Jenny is published by HarperCollins, 14.99

This article was first published in Scotland on Sunday, June 27, 2010