Replying to a question in the National Assembly by Freedom Front Plus leader Pieter Mulder, he said the law and government policy on the matter were clear.
The Constitutional Court, in its ruling that the death penalty was unconstitutional, stated: "It is only if there is a willingness to protect the worst and the weakest amongst us that all of us can be secure that our own rights will be protected".
Zuma said the Bill of Rights in the Constitution, which needed a special majority to be amended, was to protect the rights of all South Africans, including the marginalised and the minorities, who could not protect their rights adequately through the democratic process.
Mulder said the Constitutional Court had simply interpreted the Constitution, and nothing prevented the Assembly from amending that Constitution.
He called for a commission of inquiry to investigate whether the death penalty would not be a deterrent to crime.
Zuma said the Constitution was drawn up by the elected representatives of most South Africans, and one had to be responsible about the matter.
"Taking somebody's life is not a right that we must exercise. It is God's right. It is God who gives life and must take life.
"Whether you take it by a decision of the judiciary, or by shooting or stabbing, you have taken the life of a person".
Because of certain circumstances, people might have different views on the matter.
"But, I think the decision by the Constitutional Court was a very responsible decision, by very responsible judges, on this matter... and we are respecting it and we are supporting it," Zuma said.
Democratic Alliance Chief Whip Douglas Gibson said he agreed the death penalty was a sensitive matter.
"My view, is that the death penalty is justified for aggravated murders and for the murders of policemen".
The widespread call for the reinstatement of the death penalty was because government had failed to bring crime under control, he said.
Zuma said government was satisfied progress had been made in arresting and punishing criminals.
A sentence of life imprisonment - with no possibility of parole or pardon - meant exactly that, precisely because South Africa did not have the death penalty.
It was an issue that had to be discussed, Zuma said. – Sapa.