Born in Gaza, a strip of land between Israel and Egypt, Abuelaish went to a humble local school, where he studied hard and won a scholarship to study medicine in Cairo.
He went on to earn a diploma in London and a master's degree at Harvard University in the US. He was the first Palestinian doctor to work at an Israeli hospital. Now living in Toronto, Canada, he continues to spread the message of peace.
Recently, Abuelaish visited Li Po Chun United World College in Sha Tin to speak to students. "I encourage you to dream big," he told them. "Keep your soul energised and high."
He urged them to look beyond the numbers from conflict zones. "It's shameful to think of a human being as just a statistic," Abuelaish said. "These people who are killed are not numbers. They have names and stories ... We need to value lives."
Abuelaish knows the cost of human suffering first-hand. In late 2008, a conflict between Israel and Hamas, an Islamist group that rules Gaza, escalated into a ground invasion by Israel.
More than 1,000 Palestinians died during the three-week war, including three of Abuelaish's daughters - Bessan, Mayar and Aya - and his niece in an Israeli strike.
In his book, I Shall not Hate, the doctor recounts how he used to tell his children to lean against different walls to avoid being killed all at once. On that fateful day, however, his three daughters and niece chose the wrong wall to hide behind.
But Abuelaish says he has not embraced revenge against Israelis. Rather, he has decided to honour the memory of his daughters by celebrating their lives. In 2010, he founded the Daughters for Life charity in Canada. The foundation raises funds for the education abroad of girls and young women in the Middle East.
Abuelaish cites the example of Malala Yousafzai, the Pakistani girl who was shot in the head last year by Taliban gunmen for her outspoken support for the education of girls.
"Malala is a voice that was heard, but there were millions of voices that were not heard," he said. "We need more people to speak for these girls. They will be the [future] of their nation."
A Western education, he says, would open up new perspectives for Middle Eastern girls, many of whom languish in closed societies without the chance to develop their talents.
Abuelaish also had a message to Hong Kong students: he urged them to look globally and not to turn a blind eye to injustices in other parts of the world.
Conflicts arise out of human hatred and folly, he stressed, and can be solved if people dare to push for change. Often, he added, people understand the problems but still fail to act because those problems don't affect them.
Yet in a fast-globalising world, few conflicts remain local for long. That's why Hongkongers, who enjoy great freedoms and material comforts, should care about less-fortunate people in other parts of the world, such as the Middle East.
"Life in Hong Kong is linked to life in the world at large," he explained. "Peace in Hong Kong is linked to peace in other parts."
Hong Kong students should keep abreast of current events around the world and link up with other young people elsewhere through social media, Abuelaish suggested.