He added that it is pointless spending billions of pounds fighting Islamic State militants without looking at hatred towards other religions and people.
Tony Blair is also calling for an international charter that all nations must sign up to, obligating them to teach religious respect, tolerance and understanding.
He said: "Unless we begin to confront the underlying causes each time we take on a group like Isis another will quickly arise to take its place. And in order to fight a warped and worsening ideology in the long term we need to recognise that education is a security issue.
"Because each and every day the world over, millions, even tens of millions of young children are taught formally in school or in informal settings, a view of the world that is hostile to those of different beliefs.
"We need at the G20...to raise this issue as a matter of urgent global importance and work on a common charter to be accepted by all nations, and endorsed by the UN, which makes it a common obligation to ensure that throughout our education systems, we're committed to teaching the virtue of religious respect.
"This doesn't mean an end to religious schools or that we oblige countries to teach their children that all religions are the same.
"This should be a common global obligation, like action to root out racism or action to protect the environment. Nations should feel the pressure to promote respect and to eradicate disrespect."
Irina Bokova, director-general of the United Nations Educational, Scientific and Cultural Organisation (Unesco), has previously said that failing to address education is now a global security risk.
She added that poor education in some areas was causing a dangerous combination of illiteracy, unemployment and extremism.