BAIDOA, Somalia (AP) _ Each has its own baby Jesus, each its own burden of hate. But Christianity and Islam were together this Christmas, here in the land of frankincense and myrrh, feeding the hungry, healing the sick, praying for peace and good will among men.

''We say welcome to the Americans, to the Christians 3/8'' a gray-bearded Muslim clergyman beamed. ''The reception has been just terrific,'' said a visiting Catholic bishop.

The Nativity is a richly told tale in both the New Testament and the Koran. In both, the news from Bethlehem is greeted as ''glad tidings.''

But a subsequent few centuries of holy wars left a lingering distrust between the two great religions. And the Islamic holy book portrays a boy child unfamiliar to Bible readers, one who speaks to his neighbors within hours of his birth and tells them, ''I am a slave of God. God gave me the Book and he made me a prophet.''

The Jesus of the Koran is no divinity.

''Christians don't want to know the reality,'' said Hassan Sheik Mohamed, a leading Islamic clergyman in Mogadishu, the Somali capital. ''There is just one God and one religion.''

The old mullah here in Baidoa was not so righteous.

Told that the American Marines down the road would worship their Trinity in Christmas Eve services, Sheik Mohamed Hamud Hassan smiled and said, ''That's their business. We respect everyone's religion.''

The Marines in Baidoa, on the front line of the international effort to save hundreds of thousands of starving Somalis, worked hard to get up some Christmas spirit amid the swelter and squalor of this hinterland town.

Some went a-caroling through their rough encampment. Others raised a thorny tree, called it a good approximation, and hung it with empty water bottles. And some simply did what they were sent for - riding shotgun on food shipments to outlying villages.

''Look at Matthew 25,'' the Rev. William P. Joy, visiting a Catholic Relief Services station here, told a reporter. ''That's what this is all about'' - ''For I was hungry and you gave me food, I was thirsty and you gave me something to drink, I was a stranger and you welcomed me, I was naked and you gave me clothing.''

The setting for this Christian charity - or Muslim brotherhood - is almost biblical-looking: a countryside of braying donkeys, boy goatherds, loping camels, a town aswarm with robe-swathed women, rag-clad urchins, cripples, beggars, thieves, holy men.

From this ancient Land of Punt, the fragrances myrrh and frankincense were once shipped to the Arabian peninsula. From there, more than 19 centuries ago, they found their way to Jesus in the manger, in the treasure chests of the wise men.

Some Somalis are looking today for gifts from Arabia. They mutter that the oil Arabs and other well-off Muslims have not been generous enough in supporting the relief efforts that have followed years of civil war and months of famine in Somalia.

Mogadishu's Sheik Mohamed, an official of the charitable World Muslim League, disputes that.

''Islam says we must help everyone in need,'' he said. ''If they need food, we give them food. If clothes, we give them clothes.''

He said his organization has spent $5 million a month the past half-year or so on its relief activities, including 120 meal centers. One-third of the league's funds come from Saudi Arabia, he said.

''Islam says we must help everyone in need,'' he said. ''If they need food, we give them food. If clothes, we give them clothes.

''In this way,'' Sheik Mohamed acknowledged, ''the religions are the same.''

In a gesture that might make even a stern mullah smile, the visiting bishop, the Very Rev. John Ricard of Baltimore, a Catholic Relief Services board member, will ask Americans to contribute to a special good cause: replacing the roof of a Baidoa mosque damaged in the war. He'll target the appeal to U.S. Muslims.

And at Ricard's midnight Mass Thursday, under a bright green tarpaulin and the starry Somali sky, the American military men and women, far from home, might have enjoyed hearing what the Islamic faithful are told about those who listen to the word of Jesus:

''And in the hearts of those who followed him,'' says the God of the Koran, ''we ordained compassion and mercy.''