January 23, 1984

The Nissan Motor Company Ltd., the world's fourth-largest maker of motor vehicles, has just spent two years and millions of dollars successfully trying to destroy one of this country's better known automobile brand names. The 50-year-old Japanese company is in the process of abandoning the Datsun name so it can consolidate its worldwide marketing under a single corporate banner. Beginning last October, the company started promoting all its cars under the Nissan name. All older models that still carry the Datsun logotype now have a Nissan tag, too.

In a fit of delight, Carmen Fuentes kissed the wall of her apartment building. ''I'd rather kiss your feet,'' she told Dominick Cordi and Sol Riess, city inspectors bearing thermometers who had come to check the heat in her Brooklyn apartment building yesterday. ''Thank the Lord you've come.'' The men were part of a special team of 12 inspectors who spent the day investigating complaints phoned into the city's Heat Complaint Bureau; a total of 6,613 were received from midnight Friday to midnight yesterday.

Across Eastern Europe, there are signs of a religious renewal. The pattern is as uneven as the patchwork of Roman Catholic, Protestant and Orthodox faiths that crisscrosses the six junior partners of the Warsaw Pact, and it is colored by the struggles between the countries and various churches that occurred both before and after the imposition of Communism in the late 1940's. Particularly in Hungary, Czechoslovakia, East Germany and Poland, clergymen and scholars say growing numbers of people are turning to - or turning back to - churches that, under Marxist theory, should be on the road to extinction. In cities in Bulgaria and Rumania, there are reports of increased churchgoing, but few signs of a major revival. Not a Mass Movement With the exception of Poland, where the Roman Catholic Church is the guardian of national aspirations, the movement of renewal is not a mass phenomenon. Rather, active Christians are normally a minority in societies that have become secularized through industrialization, Communist propaganda and persecution.

Angola, reacting to major military gains by rebel forces, has begun a major counteroffensive against the South African- backed guerrillas, according to diplomats and other authorities in Europe. But these authorities, who include diplomats and Portuguese and African officials, said the rebels, led by Jonas Savimbi, may have become too powerful for Angola to defeat them militarily. These military developments come when, in addition to its civil war with the rebels, Angola has become deeply embroiled in another conflict with international ramifications: the fight over South-West Africa, or Namibia, which lies across its southern border. South Africa, which rules Namibia in defiance of the United Nations, has occupied territory in southern Angola since 1981 in an effort to root out guerrillas from the South-West Africa People's Organization, who have been fighting against Pretoria's domination of the territory for 17 years.

When Apple Computer Inc. introduces its long-awaited Macintosh computer tomorrow, it may represent the last serious assault on the dominance of the International Business Machines Corporation in the personal computer industry. The Macintosh, unlike many personal computers introduced over the past year, is completely incompatible with the I.B.M. Personal Computer. Thus, it is a gamble for Apple because many of the most widely used computer programs on the market are designed for the I.B.M. machine. ''They are taking an awesome risk,'' said David Lawrence, an analyst for Montgomery Securities in San Francisco. ''The bottom line is 'Can you establish an alternative to I.B.M.?' ''