S. Africa's white NG Church pays a high price for developing race policy

South Africa's powerful and influential Dutch Reformed (Nederduitse Gereformeerde or NG) Church is suffering from serious dissent within and being shunned from without.

Turmoil and isolation are the prices the church is paying for its role in supporting and to some extent helping formulate South Africa's apartheid (racial segregation) policies.

But whatever effect these pressures have on the church, experts here do not expect Pretoria to lose suddenly the theological footing the church has provided for apartheid.

The latest - and highly significant - blow is the suspension from membership of the NG Church and its smaller sister Nederduitsch Hervormde Church by the World Alliance of Reformed Churches (WARC).

WARC is one of the world's oldest and largest ecumenical church organizations. The NG Church has clung to its WARC membership as it faces mounting isolation elsewhere.

This year five sister reformed churches outside South Africa broke dialogue or refused closer fellowship with the NG Church. But the WARC suspension carries more sting.

''Lots of other churches have stopped talking to us. But this is like getting thrown out of the house,'' says Dutch Reformed theologian David Bosch.

The NG Church is considered the most important church in South Africa since it provides a theological justification for the government's segregationist policies. Withdrawal of that religious endorsement would be a severe blow to South Africa's entire political and social power structure.

According to the NG Church, the Biblical account of the scattering at Babel shows a divine intention in the diversification of mankind. Particularly in South Africa, with all its ethnic diversity, the church finds Scriptural justification for a policy of ''separate development'' that perpetuates this initial differentiation of man into various language, cultural, and eventually racial groups.

The NG Church derives its clout in South Africa from the fact that it represents two-thirds of the dominant Afrikaners, including most of the government leaders. The church maintains considerable influence over government policies by endorsement or quiet acquiesence. The ruling National Party, the secret political-cultural Broederbond, and the NG Church are mutually influential when it comes to establishing each group's leadership and operative ideology.

The WARC action is just short of total expulsion. It means the two South African reformed churches are barred from voting and cannot hold office in the alliance.

For readmittance, the WARC insists the South African churches reject apartheid, stop excluding blacks from services, and help those suffering from racial segregation.

Similar demands have gained momentum from within the ranks of the NG Church and may be debated at the church's once-every-four-year general synod, to be held in October.

Recently 123 ministers, whose numbers have since swelled to 150, sent an open letter to the NG Church condemning its support for apartheid policies.

However, the church is under just as much pressure from members who say it is not doing enough to slow down change.

Just as worrisome for South Africa and the NG Church is the likelihood that local Colored (mixed race) theologian Allan Boesak will become the new president of the WARC.

Boesak is a member of the Colored branch of the racially divided NG Church. He led the move at a WARC meeting in Ottawa to have the NG Church expelled. Dr. Boesak considers apartheid heresy. He favors a racially united NG Church.

Dr. Boesak submitted a paper at the WARC meeting stating that while racism was not exclusive to South Africa, the role of the reformed churches in supporting the ''structure of oppression'' was unique in the world.

The NG Church says its ''separate development'' policy is not an endorsement of discrimination. While it shows no inclination to unite its racially divided structure, it insists it is an ''open'' church, meaning blacks can attend white services.