AS DAWN BREAKS on Sundays over this hilly capital, the liturgical chant of Coptic priests drifts across the city mixing with the pungent smell of eucalyptus wood burning on early-morning home fires.

Thousands of silent ghost-like figures, wrapped in the ubiquitous white-cloth Ethiopian shama used to fend off the cold, can be seen making their way to the churches that dot the hills and dales of this 8,000-foot-high city nestled up against the Entoto Mountains.

Stripped of its wealth and once-powerful political influence by a radical revolution gone Marxist, Ethiopia's 4th Christian Coptic Church is nonetheless enjoying a new popularity and apparently thriving on adversity in the best early Christian tradition.

The celebration of Maskal last September, a Coptic ritual that celebrates the end of the rainy season and the discovery of Christ's cross, drew a huge crowd to Revolution Square, dominated by enormous portraits of Marx, Engels and Lenin. According to some accounts, it was the biggest turnout since the onset of the revolution in 1974.

"I can't believe the number of people I see going to church these days," remarked a high government official, as much perplexed as alarmed by this sign of lack of public Ethiopian faith in the country's new official religion of Marxism-Leninism.

Before the revolution, it was estimated that 40 percent of the population, now 32 million, adhered to the Coptic faith and about as large a percentage to Islam. But there was a sharp falloff in church attendance after the upheaval as young people in particular sought salvation in Marxism instead.

The struggle between Ethiopia's old and new religions seems to have been deliberately highlighted by the government's decision to close off the main avenue to the Church of the Trinity, the city's main Coptic cathedral, to build headquarters for the embryonic Communist Party.

It is disputable just what this Ethiopian-style Born Again movement really means. A tour of the churches on an early November Sunday found few young people in attendance. But it does serve as an indicator of the return to normalcy and tradition in this country-wracked for six years by wars, famine, and domestic political turmoil.

It is a trend the military government welcomes, and some say is promoting as part of a policy of "controlled relaxation." The policy is aimed at consolidating its support and overcoming the intense politicking that until recently generated such bloody warfare among civilian factions supporting and opposing its rule.

ONE OF THE NEW "institutions" to emerge from the revolution has been a veritable cottage industry of small home restaurants. These are invariably run by wives of the fallen Ethiopian aristocrary, which lost its land and all real estate but a single home per family in the revolution.

A monthly government stipend of $125 is all most have to live on now, and this has driver many of the old aristocrats, or more precisely their wives, into the home restaurant business. They are all over the capital, unmarked by signs or any other indication of their existence except perhaps a large number of cars parked outside.

One such restaurant was easy for me to find, however. It is in the house of the former Washington Post bureau here and run by the widow of a knight in the old aristocratic order who was my landlord.

Dressed in traditional Ethiopian clothes, Wozoro Abonesh Girma greets her guests with a warm smile and leads them to what was once the living room. For $2.50, she dishes up all the pancake-shaped injera , meat and hot spicy wot , the basic ingredients of all Ethiopian meals, one can possibly eat.

With prices like these, she and other aristocrats-turned-restaurateurs are understandably doing a roaring business. But it is a style of life Ethiopia's former high and mighty never dreamed would one day be theirs.

THE GOVERNMENT has finally lifted some of the mystery surrounding the life and career of Mengistu Haile Mariam, the junior officer who outwitted a host of rivals and reportedly survived nine attempts on his life to become the undisputed leader of Ethiopia's revolution in early 1977.

At the onset in 1974, virtually nothing was known of those making up the shadowy Provisional Military Administrative Council that toppled the last Emperor Haile Selassie and the Ethiopian monarchy except that they were low-ranking army officers. Even after Mengistu emerged as "Comrade Chairman" of the council, his origins and history remained obscure.

On awarding him the Order of the Star of Honor of Socialist Ethiopia late last year, the government confirmed rumors that he was the son of an army sergeant and identified him as Haile-Mariam Wolde. It said his mother was Wozero Bizunesh Wolde-Amanuel, the daughter of a "former oppressed tenant," who died when he was 10 years old.

He was born in the capital and atended schools here and "other parts of the country," an apparent reference to his roaming life as he followed his father from barracks to barracks. The official account confirms he never finished his formal secondary education, explaining that "because of his burning zeal to join the army" he dropped out to enroll in an unnamed military training center, believed to be Holetta not far from the capital.

But he reportedly took advanced courses in political science, law, and economics "at college level in and outside the country" in addition to advanced military training in unnamed Western countries, one of which is known to have been the United States.

Commissioned a second lieutenant, Mengistu spent 15 years in the Third Army Division in southeastern Ethiopia, participated in an abortive 1960 military coup against Haile Selassie and was denied promotion because of this, and finally "was one of the young officers who spearheaded" the 1974 revolution.