The First Commandment of Christianity and the First Pillar of Islam begin virtually identically: There is only one God and no others should be worshipped.

Placed against a Jan. 15 deadline that poses a real threat to peace on Earth, the geography and the Christmas gospel have been touched with a here-and-now urgency in the Middle East, where the roots and enmities of Christianity, Judaism and Islam are intertwined.American troops are "strangers in a strange land" in Saudi Arabia. And religious differences are at the intersection of this cultural collision.

To understand those differences requires appreciating the common ground of Christianity, the faith of many Americans now stationed in the Persian Gulf, and Islam, the religion of Muslims and the official state religion of Saudi Arabia.

"I don't think it's generally understood in the United States that Islam, Christianity and Judaism are so close, that they arise from the same place geographically and internally," said John Woods, director of the Center for Middle Eastern Studies at the University of Chicago.

"All are monotheistic and believe in the same series of prophets."

The Persian Gulf is at the eastern edge of topography that holds Islam's holy cities of Mecca and Medina, as well as Jerusalem, a holy city to Muslims, Jews and Christians, and Bethlehem, the birthplace of Jesus.

But just as the Five Pillars comprising Islam's basic tenets differ greatly from the 10 Commandments guiding Christianity, this shared Middle Eastern geography holds both common and conflicting religious beliefs.

Muslims believe Jesus was a prophet, born of the Virgin Mary, that he ascended into heaven and that he will come to Earth again. But as similar as that is to Christianity, Muslims do not believe that Jesus was the son of God or that he was crucified.

Muslims believe God's direct words to them, revealed to the Prophet Mohammed and written in the Koran, recognize Christianity as a scripture-based religion that qualifies for protection by the Islamic state.

"Christians, Jews, Sabians and Zoroastrians are recognized by the Koran as people of the scripture," Woods said.

He and Cyril Glasse, a comparative religion scholar and author of "The Concise Encyclopedia of Islam," said Sabian was a name used by various groups at various times in history, and the Koran seemed to cite it to enable Muslim tolerance for various religions.

As members of Koran-recognized religions, Christians and Jews have the right to practice their faiths in their homes, churches or synagogues under the authority of the Islamic state, but "they are not allowed to be overtly public lest they detract from the Islamic society," said Imam Jamal Said of the Mosque Foundation of Chicago.

"For that reason," he said, "public displays of Christianity, including crosses, are not permitted under the Islamic state, but private use of symbols related to the religion would not be banned."

Glasse, a practicing Muslim, explained how Islam recognizes Jesus as being born of the Virgin Mary without being the son of God, and ascending into heaven without being crucified:

"The Koran says Jesus did not have a human father but was God's word cast into Mary; and that Jesus did not die on the cross but rather people only saw him die. Muslims don't believe Jesus was resurrected after crucifixion but that somebody died in his place on the cross."

Said, whose "imam" title designates him as the religious leader of a Chicago Muslim group, said Muslims believe "in the miracles of Jesus as provided to him from God," and that Jesus will return and "correct those who claimed for him that he was a Son of God, since he never claimed this position for himself."

Belief in the deity of Jesus is where Christianity diverges from Islam and Judaism; and Muslims separate themselves from Christians and Jews by holding that all prophets were preaching Islam, but followers of Christianity and Judaism have misinterpreted the message, Glasse and Woods said.

Comparing Iraq to ancestral Persia, which forced Europeans to forge new alliances in the holy Crusades centuries ago, Glasse said Iraq is again a catalyst for new alliances such as the U.S., Soviet Union and Saudi Arabia.