Children should be taught at school to challenge racism and discrimination, the mother of Stephen Lawrence has said.

In a Guardian article to mark the first national commemorative day for Stephen, murdered in a racist attack 26 years ago, Doreen Lawrence said discrimination still blights lives.

She wrote that children needed to be taught “to challenge racism and discrimination and to embrace inclusion”.

The first Stephen Lawrence Day on 22 April comes amid a rise in hate crime and rightwing extremism.

Lady Lawrence wrote: “If we are to encourage future generations to build a better society, free from discrimination, I believe that we must teach tolerance and inclusion from an early age. Education is a powerful way of inspiring young people, and I would like to see British schools put the values of respect and fairness at the heart of the curriculum.”

Stephen, 18, was stabbed at a bus stop in south-east London on 22 April 1993 by a white gang. Police blunders meant it took 19 years to jail two people for the murder and at least three other suspects remain at large.

The Macpherson inquiry found that institutional racism blighted the police response and for a quarter of a century debate has raged about the level of prejudice in Britain and how best to tackle it.

Lawrence said prejudice remained in professions such as architecture, which Stephen hoped to join. “Stephen was someone who had a passion for drawing and aspired to be a young architect. But even 26 years after his death, a recent survey of more than 900 UK-based architects and students showed that over a quarter thought racism was widespread in the profession.”

Duwayne Brooks, Stephen’s friend who was with him and survived the attack, told the Guardian that 26 years on justice had not been done. “None of us have had justice. All those involved in the murderous attack on Steve have not been convicted and everyone knows who they are, but the justice system has not worked.

Duwayne Brooks survived the attack that killed his friend Stephen Lawrence. Photograph: Peter Macdiarmid/Getty Images

“There are many cases like that where the victims’ family is still feeling the loss and the killers are still free, and their cases have not even reached the local media.”

Stephen’s father, Neville Lawrence, said his anger had dissipated and he had managed to put his son’s killers out of his mind. “I am relaxed. I worry about normal things. I do not worry about these people. They will have to answer for what they have done sooner or later,” he said.

“The anger is gone and I don’t think about Stephen’s killers any more, I just get on with my life.”

Stephen’s father, Neville Lawrence, says he no longer thinks about his son’s killers. Photograph: Kirsty O’Connor/PA

Theresa May said of Stephen: “His life stands as an example. A reminder of the work we must do to ensure that young people, no matter what their background, are given every chance to fulfil their ambitions.”

The prime minister added: “Stephen’s murder was a watershed moment for our country. It was a moment that demanded we wake up to the reality of the racism that still exists in our society and the obstacles that far too many young people live with every single day of their lives.”