The largest branch of South Africa's white Dutch Reformed Church is coming under increasing internal strains because of its continued support for the government's policy of separate racial development, or apartheid.

Because of its refusal to form one united body, angry ministers in the black, Indian and Colored (mixed race) Reformed churches are threatening to end their affiliation with the white church -- known as the Nederduitse Gereformeerde Kerk, the most prominent of three branches of the Reformed faith in South Africa.

Such action would leave the white church, to which most of the Cabinet members and over half the country's ruling call of 2.5 million Afrikaners belong, domestically isolated, compounding its almost complete quarantine from international church bodies.

Meanwhile, a minority of white Dutch Reformed clergymen are distressed by their church's failure to move away from its close identification with the government. Recently four white ministers took the rare step of publicly resigning from the church to protest its failure to criticize government policies.

Among them is Beyers Naude, a prominent opponent of apartheid who was already under a government banning order restricting his social contacts because of his criticism of government policy. Naude, 64, joined a black Dutch Reformed church.

Peter Schoeman, who left with Naude, is a nephew of a former Cabinet minister who served in the National Party government for 30 years. Schoeman, 36, is trying to set up a multiracial congregation in Pretoria.

Some observers say the rising disaffection of the nonwhite or "daughter" churches and the defection of the four ministers are signals of a significant internal crisis for the white Dutch Reformed Church.

"There's no historical parallel for what's happening, it's from within the family," said one of the ministers who left.

"The Dutch Reformed Church's credibility is at lowest ebb now and it is its own fault," said philosophy professor Willie Esterhuyse, a leading layman in the church and author of a recent book criticizing it for not playing a more activist role in fighting discrimination.

Black and Colored churchmen say they are finding it increasingly difficult to justify to their parishioners a continued affiliation with the white church. t

"When you say you are in the Dutch Reformed, people say, 'Oh, the government church, the apartheid church," said a Cape Town Colored minister, John Hartney.

"For me, the parting of the ways has come," said Allan Boesack, a Colored Dutch Reformed minister and theologian. He favors a break with the white church so the nonwhite churches can concentrate on a "total change in the system."

"The watershed is the present crisis [of unrest]. What is at the root of it is the system of apartheid. The white church is just as responsible for the crisis as the government is," Boesack said.

Relations between the daughter churches and the white church recently worsened when the white church refused to say publicly that it would not object if the government decided to "reconsider" the laws against interracial sex and marriage.

These laws underpin the apartheid structure and have always had the blessing of the white church.

So protective of the status quo is the white church at the moment that it is actually retarding the limited social change Prime Minister Pieter W. Botha would like to make.

According to church sources, Botha had discreetly let it be known in private meetings with church leaders that he would welcome church support for a change in the sex laws so he could more easily move to change them over right-wing opposition.

In the midst of the current disturbances in black and Colored communities, the white church complimented the police force for its restraint but made no public criticism of the segregated educational policy that has been a cause of the unrest.

But it is the white church's refusal to consider appeals for unity from its daughter churches, whose total membership is just over a million, that is the main issue.

"They believe that once you have a united church, integration will follow," said a Colored minister, Esau Jacobs.

Boesack and some other ministers have requested an extraordinary synod this year, two years ahead of schedule, to discuss the unity issue. It is unlikely that the white church will agree to hold it, but Boesack predicts that whenever the next synod is held, "without a doubt something decisive will happen one way or another."

Nonwhite ministers who want to see a united Dutch Reformed Church have established an informal grouping called the Brothers Circle, which many consider the basis for a future united church. "This is a vehicle for unity, which is already very strong in the minds of the people," said Jacobs.

The biggest obstacle to a split is money. More than half of the daughter churches' budgets come from the wealthy white church. "Money is the only thing intimidating us" from splitting, Boesack admits.

The white church realizes this and believes its financial leverage will prevent a major rupture. Publicly, most white church officials say Boesack and the "Brothers Circle represent only a radical minority in the nonwhite churches.

The deterioration in relations between the white church and its affiliated nonwhite churches worries many young white ministers and laymen.

"A lot of verkramptes [hard-liners] see the church as the last bulwark of conservatism," said Esterhuyse, a Stellenbosch University professor. "But the time has arrived for the church to proclaim the Bible's teachings prophetically whatever the consequences may be. It's not the task of the church to justify the status quo."

Furthermore, the conservatism of the white church has left it even more isolated internationally than the government. While Pretoria has diplomatic and economic ties with many countries, the white church has links with only two international orthodox Calvinist bodies.

But most of the questioning white church members still hope to reform the church from within. They would agree with Esterhuyse that "you won't get the white church to accept a resolution to say separate development is immoral. Its function in the next decade will be to try to point out the immoralities with the system, not the system itself."

The four ministers who recently resigned believe that is inadequate. "It's impossible for the church to give a contribution to racial justice while it is solely a white church," said Schoeman.

Schoeman predicted an apocalyptic future for his former church.

"They'll whine and carry on, convinced that God is going to be on the side of the Afrikaner come what may," he said. "But they'll be surprised. God will ditch them. History will carry on."