The new South Africa, if it is ever born, will not lack for leaders. A Glimpse of those who might take over if the country is freed from apartheid was given at the Robert F. Kennedy Human Rights Awards at Georgetown. Two of the winners were prevented by their government from attending the ceremony.

They were vividly represented. The Rev. Allan Boesak, founder of the United Democratic Front, sent his wife, who read his acceptance speech with much spirit, and his 8-year-old son, Allan Jr. Winnie Mandela, wife of Nelson Mandela, who is serving a life term in prison, had her prize accepted by Bishop Desmond Tutu's daughter. Mpho Tutu, a U.S. college student, looks and sounds like her famous father. She referred to Winnie Mandela as "the first lady of South Africa."

The third recipient, the Rev. C.R. Beyers Naude, spoke for himself, and memorably. When Naude, scion of a preeminent Afrikaner family, was a rising star of the Dutch Reformed Church, he was spotted as a future prime minister of South Africa. But that was before he renounced apartheid, a heresy that led to his forced resignation from the ministry, and later, banning.

Naude is an orator of such force and fire that it was astonishing to hear him in Washington, where so many say so little and expect to be praised for their good judgment or at least their powerful survival instincts. If a free South Africa is seeking a prime minister of proven valor and eloquence, Naude may revive the speculations of his younger days.

He began by praising the judges for their selection of a white man (himself), the son of a black man and a white woman (Boesak) and a black woman (Winnie Mandela). It was, he suggested, the kind of coalition that explains the force of resistance and the promise of a new South Africa.

Naude is nearing 70, a man with straight gray hair and a serious face. He said things that could easily cause the authorities to seize him when his plane lands back in Johannesburg.

He said of apartheid: "Such a system cannot be reformed. It has to be removed. And if it refuses to be removed, it has to be destroyed."

That could easily be reckoned as subversive by the desperate and obdurate men in South Africa, who are shooting into crowds, jailing children the age of Allan Boesak Jr. and whipping men and women in the streets.

Naude, when asked about the danger that could face him at home, said, almost jauntily, "I am aware of that, but I deliberately said it, because there is no point of going around it."

He spoke with great passion about Nelson Mandela. "As long as Nelson Mandela is forced to remain in prison, South Africa will also remain imprisoned. Only when Nelson Mandela is free will the whole of South Africa, black and white, be free."

He put America's obligation in terms stronger than our politicians dare use.

"If the U.S.A., economically the richest and militarily the most powerful nation on Earth, claims not to have the power to terminate the power of apartheid, then there is something drastically wrong either with the nature of that power or with the ability or the willingness of your country and its people to utilize such power in the service of justice.

"God has a funny way of confronting human beings and human societies at the most awkward moment of their existence of history," he told his mesmerized audience at Georgetown, "with their refusal to face up to themselves -- which is exactly what God has been doing with South Africa during the last 12 months. Here is a classic example of a country which refused or delayed to face up to its situation, and now the moment of truth has arrived. The answer must be given -- and white South Africa is neither ready nor able to give that answer."

But, he said, there is a solution: democracy.

Dorothy Boesak read her husband's acceptance speech, saying, "Our people have risen up from the ashes and claim with dignity and pride their rightful place in the land of our birth."

Winnie Mandela was shown on a short film, speaking somberly of the "20th-century slavery" that apartheid imposes on blacks and the miserable failure of "constructive engagement," President Reagan's way of expressing moral outrage.

The whole affair was a refutation of the concern that there is no alternative to the Botha government, with its whips and its guns. The bright, brave, eloquent people against apartheid have talent as well as a dream.

The awards were presented by Mrs. Robert F. Kennedy on the day that would have been the senator's 60th birthday.