President Jacob Zuma said on Thursday he was humbled by the work of non-profit organisations (NPOs).
He was helped by a social worker after he was released from prison, he said in Boksburg.
"So, I have personal experience of how you impact on this country," he told a conference hosted by the department of social development.
Government support of NPOs had been extended with the establishment of the National Development Agency (NDA).
Zuma advised NPOs to find out about the NDA to strengthen the sector.
"We urge the private sector as well not to make the NPOs the first area of focus when they have to undertake financial austerity measures."
They should appreciate how NPOs helped to promote social cohesion and stability in society.
"This diverse sector must be supported in order for it to grow and continue supporting our people," Zuma said.
"There are now about 100,000 organisations in the NPO sector and more than 85,000 are registered in terms of the NPO Act."
