Such obstacles would not only hinder unity but block the government's efforts to create a new Malaysian race, he said.
He said the situation was different in neighbouring countries like Indonesia, the Philippines and Thailand.
"There, the people of various races, languages and cultures accepted one identity for the sake of the nation and their future.
"We, in Malaysia agreed that each would retain their identity. It was agreed upon under the social contract at that time (1957).
"Nevertheless, we retained the identity of the original country. Because of that, we don't want to change, (and as such) there will never be a true Malaysian," he said at a press conference after attending a discussion on the evolution of the identity of the young Malaysian.
He said the national education curriculum should emphasise the development of a noble personality and not just focus on knowledge, so as to create a credible generation.
"We give our young all types of knowledge but we do not develop their personalities. This could result in the knowledge being misused," he said.
Dr Mahathir said he was satisfied with the Gross Domestic Product of 6.3 per cent for the first six months of this year, compared to the 4.4 per cent during the same period last year.
"It is really good. We can grow faster if we do not have the economic disparity among the races.
"If we only give importance to growth without equal distribution, it can lead to tensions among the races," he said.
Yesterday, Bank Negara Governor Tan Sri Dr Zeti Akhtar Aziz said the country was expected to register an economic growth of more than 5.5 per cent this year due to stable performance during the first six months of this year.