On a cool but sunny December day in Gaza, Dr Izzeldin Abuelaish took his eight children to the beach for the simple pleasures of paddling in the Mediterranean and playing in the sand.

Two months earlier, the children's mother had died from acute leukaemia, and Abuelaish was comforted to see his older daughters laughing and chatting as they wrote their names in the damp grains close to the water's edge: Bessan, Maya, Aya. "It was as close to heaven and as far from hell as I could get that day," he later wrote.

But within five weeks the Abuelaishs were to suffer a second tragedy: those three girls, aged 13, 15 and 21, were killed, and another daughter, Noor, 17, seriously injured, when an Israeli shell was fired at the family home during the brief but bloody war in Gaza in 2008-9. One of Abuelaish's nieces also died; a fifth girl, another niece, suffered terrible injuries.

Many in his situation would have descended into a dark, lonely pit of grief and bitterness. But Abuelaish not only rebuilt a life for himself and his surviving five children, he has written a moving and powerful book about his experiences with a central message of hope and reconciliation.

I Shall Not Hate – published in Canada in April, and out in Britain in January – has had an extraordinary impact. Sitting in the home of his extended family in Jabalia, northern Gaza, Abuelaish – back on a month-long visit from Canada where he now lives and works – reads out emails on his BlackBerry from strangers expressing their sympathy, gratitude and support.

The book has been translated in 13 languages, from Finnish to Turkish – but most importantly copies will soon be available in Hebrew or Arabic. A book tour in the US is scheduled for January; proceeds from sales and appearances will go to Daughters for Life, the charitable foundation Abuelaish set up.

He explains his choice of title. "I'm against any violence. Violence and the military approach proved its failings decades ago and that will never, ever change. No one evaluates; we just continue blindly.

"As Palestinians and Israelis we have failed to change course. We just continue with the same approach which aggravates, escalates and widens the gap of hatred and bloodshed. It's easy to destroy life but very difficult to build it."

Would it not be understandable to feel hate after what has happened to him? "There is a difference between anger and hate. Anger is acute but transient; hate is a poison, a fire which burns you from the inside. We need to be angry, but direct it in a positive way."

Abuelaish, an obstetrician and gynaecologist specialising in infertility, spent years working in Israeli hospitals where, he says, patients were surprised to find a Palestinian doctor delivering Jewish babies. After his wife, Nadia, died in September 2008 he went back to work following encouragement from his elder daughters, returning to his family in Gaza at weekends.

He was at home when the onslaught on Gaza began on 27 December that year. There was a "symphony of weapons, shelling" around the extended family's home in northern Gaza, where much of the action was concentrated. Everyone's nerves and emotions were constantly on edge, he says.

Throughout the conflict, Abuelaish was in regular contact by phone with Israeli friends, including journalists. His accounts, in fluent Hebrew, of what was happening inside Gaza – closed at the time to foreign journalists – were broadcast in Israel and beyond.

On 16 January 2009, at 4.30pm, a shell struck the house. He ran to the room that had been hit. "I saw my girls drowning in a pool of blood," he says, tears in his eyes. "I saw their body parts, a decapitated head, brains on the ceiling." A second shell followed.

Desperate for medical assistance, he called his friend Shlomi Eldar, a presenter on Channel 10 in Israel. His cries for help in a mixture of Hebrew and Arabic were broadcast live. Within an hour, with the help of his Israeli friends, Abuelaish's injured daughter and niece were evacuated from Gaza.

At the time, he could only think of the catastrophe that had befallen his family. Later he realised the impact of that live phone call. "It opened the eyes of the Israeli public. The secret about the war in Gaza was disclosed," he says.

The then Israeli prime minister, Ehud Olmert, watched the broadcast. "I read that he said: 'Who can see Izzeldin and not cry?'" says Abuelaish. "Two days later he announced the ceasefire. I hope that at least the blood of my daughters was not in vain, that it saved others."

The doctor was already considering a job offer in Toronto and within six months he had begun a new life as a professor in global health at the city's university. Back home for the summer holidays, Abuelaish says Gaza is "getting worse and worse".

"People are frustrated and hopeless. Wellbeing is not just dependent on having food. We are hungry for freedom, a brighter future, a secure life, for feeling our humanity."

But, he says, Gazans must not simply blame others, but take responsibility themselves. "Everything is possible in life, even peace. The only thing that is impossible is to bring my wife and daughters back. You have to keep moving. Tragedy does not define my life, but these tragedies have made me move faster."

Abuelaish's book and the foundation are his monument to his dead daughters. "I swore to God that one day I will meet my daughters and tell them their blood was not wasted," he says.

The foundation is dedicated to promoting health and education among girls and women in the Middle East. "My life is in debt to my mother, my wife, my daughters," he says. "All change starts first with the mother. If we want to change, we must start with women."

Abuelaish thinks back to the day on the beach, a picture from which graces the cover of his book. "Two weeks before the war came, [the girls] wrote their names in the sand. Where are their names now? Written in stone on their tombs. But I tell you one day their names will be written in metal and stone at schools and medical institutions dedicated to their memory. Words are stronger than bullets. We have to offer a message of hope to those who believe in hate and revenge."