Roman Catholic Christopher Columbus claims the New World in the name of Jesus Christ.

Fifty years after "under God" was added to the pledge as a Cold War riposte to the atheistic Soviet Union, the Supreme Court will consider this fundamental question: When teachers in public schools lead children in reciting the phrase, are the students praying or merely expressing their love of country?

The court will treat this as a legal question. But for many Americans, the issue is a theological one, and it is difficult, if not impossible, to tease the two apart.

"I think this case raises two questions no one can duck," said Steven Aden, chief litigation counsel for the Center of Law and Religious Freedom. "Does God exist or not? And second, where do the rights of man come from? Thomas Jefferson said all people are endowed by their Creator."

The national controversy over the Pledge of Allegiance began after a federal appeals court in California ruled in February 2003 that "under God" must be omitted when public school students recite the pledge. The appeals court said the government was endorsing religion in public schools, siding with a California atheist who sued to stop the pledge from being said in his 9-year-old daughter's elementary school.

The Bush administration and some religious groups defend the pledge, saying it is not an expression of devotion to God but merely a saying that is part of America's heritage.

Many religious leaders agree. "It cannot seriously be maintained that the words `under God' in the Pledge of Allegiance constitute the establishment of religion," said William Donohue, president of the Catholic League for Religious and Civil Rights in New York.

"Ultimately, what is at stake is the right of Americans to celebrate their religious heritage on public property without fear of reprisal," Donohue said.

In a brief filed in support of the California atheist, 32 Christian and Jewish clerics criticized the religious portion of the pledge, regardless of whether it is meant as a serious affirmation of faith.

"If it is taken seriously, then every day the government asks millions of schoolchildren to affirm and reaffirm their religious faith," the brief said.

"This request is made to children who believe in a single God whom the nation is under, and equally to children who believe in no god, many gods, or god as a concept so abstract and remote that it is meaningless or inaccurate to speak of being `under' God.

"If the religious portion of the pledge is not intended as a serious affirmation of faith, then every day the government asks millions of schoolchildren to take the name of the Lord in vain."

Advocates of the pledge have predicted the Supreme Court will strike down the California appeals court's decision for legal as well as political reasons. They said the justices are likely to be influenced by a spiritual awakening emerging across the country and by hardened patriotism after the terror attacks of Sept. 11, 2001.

"In post- 9/11, the challenge to the Pledge of Allegiance is as much a challenge to a patriotic expression as it is to a religious statement," said Jay Sekulow, chief counsel of the American Center for Law and Justice.

But opponents argue that in reciting the pledge, students are forced to acknowledge that God exists.

The religious debate that will unfold in the Supreme Court mirrors the conflict that Michael Newdow, the California atheist who filed suit, has with Sandra Banning, the mother of his daughter.

Banning, a born-again Christian who never married Newdow, said her daughter is not opposed to reciting "under God" in school.

The couple's acrimony over the existence of God threatens to pull the Supreme Court into a theological minefield, experts said. If the court strikes down the case, critics of the suit said, it would be an implicit endorsement of atheism, saying that God does not exist.

"Michael Newdow wants to replace one supposition with another one: that we can't know if God exists," said Aden of the Center for Law and Religious Freedom.

"If government institutions are predicated on the supposition that we don't know if God exists and we have to function as if he doesn't, we will have adopted an atheist position, and that is anathema to what the founders believed and what most Americans believe today."