WASHINGTON, May 3 -- From the very outset of his papacy in 1978, John Paul II has spoken of his desire to reconcile the "two lungs" of Christianity -- the Western and the Eastern, the Catholic and the Orthodox.
But just before the frail pontiff's scheduled arrival in Athens Friday, a local bishop suggested: "We ought to receive him as if he were the Mufti of Tehran."
As the French daily Le Monde put it, the head of the Church of Rome could expect no more than "minimal courtesy" in this country -- 97 percent of whose citizens adhere to a faith that seems almost identical to his.
We live in an era marked by hostility to historical thinking. This is why many find it impossible to plumb the distrust, rancor, nitpicking, jealousy, and at times outright hatred that has built up between the Eastern and the Western church since the early days of Christianity, and especially since the Great Schism of the year 1054.
On July 16 of that year, the Papal legate Humbert of Silva Candida stormed into the church of Holy Wisdom in Constantinople, then capital of the Eastern Empire, now part of Turkey. He placed a bull on its high altar, a written mandate excommunicating Michael Cerularius, patriarch of Greek Christendom. This document ranked Celularius "with the devil and his angels" and ended with a triple "Amen."
One must go back that far and much further to understand why almost a millennium later Orthodox militants are returning Humbert's compliment by calling the present Pope "a two-horned heretic" and "a devil in disguise."
The secular West may occasionally suffer from historical amnesia. Not so the orthodox East whose church sees herself as a faithful guardian of the treasures of the faith, the liturgy, the language of the New Testament (Greek), the church fathers, and especially the traditions of the first seven councils.
These councils are of utmost importance to Orthodox church life.
Any move the Vatican might make in response to new geopolitical circumstances, triggers historical reflexes among the Orthodox. They evoke collective memories going back step by ugly step.
Talk to an Orthodox observing the current Catholic resurgence and he will tell you that in the 15th century, Rome would not help his spiritual forebears against the Turks unless they submitted to the Vatican's supremacy.
Then you will hear how the Crusaders ransacked Constantinople for four days in 120. You'll hear about the schism of 1054, about serious or petty theological frictions in the preceding centuries.
Ultimately, though, you will get to the core of all hostility:
Since very early in church history there has been a gulf between the Latin West and the Greek East. And the dividing line has always cut clear through the Balkans, where it separates Catholic Croats from the Orthodox Serbs to this day, even though they speak the same language.
When Greece sympathized with Serbia's dictator Slobodan Milosevic, it did so out of "solidarity" with its Orthodox brethren who are supposedly under attack by their Catholic adversaries. And these have been whipped up by Rome, some Orthodox aver.
In June, the Pope will visit the Ukraine, again intending to heal wounds. In this case they were caused by the fact that four centuries ago formerly Orthodox churches in that country joined Rome, but retained the Eastern rite.
Under Soviet rule, these so-called Uniate churches were outlawed and persecuted, often with the assistance of the Russian Orthodox Church. John Paul II, a native of neighboring Poland, was painfully aware of this situation that ended with the collapse of the Soviet empire.
Now the Uniates are thriving again, but this, too, prompts ill feelings that are historically rooted. For the estrangement that eventually led to the Great Schism of 1054 has somewhat similar origins: Rome's dispatch of Latin-rite missionaries to orthodox Bulgaria in the 9th century.
From today's perspective, the issues that plagued Christianity's two lungs in the first millennium often seem absurdly petty. Before being excommunicated in 1054, the Eastern Patriarch Michael Cerularius, who was fiercely anti-Western, accused their Latin brethren of being "half Jews" because they used unleavened bread in the Eucharist and fasted on Saturdays.
He condemned as anathema the Catholic tradition of dropping the Hallelujah from its liturgy during Lent, a tradition that has survived in Catholicism and some Protestant denominations.
Perhaps the most important theological issue separating the churches of the East and the West may strike the uninitiated as arcane, although it isn't really because it deals with the nature of God.
In 325 A.D., the Council of Nicea agreed on the most important of the three creeds most Christian churches share. The third article of this Nicene Creed speaks of the third person of the Trinity
Originally it said, "We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father." However, at the Third Council of Toledo in 589 the Western church slipped in the Latin word filioque, meaning "and the son." Ever since, Catholics and liturgical Protestants have affirmed that the Spirit proceeds from the Father as well as Christ.
The Orthodox have always opposed this formula violently, and it is to this day one of the most troubling theological points of friction between the "two lungs of Christendom."
It is doubtful, though, that the filioque question will come up during the Pope's brief stay in Athens Friday. After all, it is the purpose of the first journey of a pope to Greece in 1,200 years to retrace the steps of the Apostle Paul and to reconcile the "two lungs."
On Satuday, things will be different in Syria, where John Paul II will commemorate Paul's conversion on the road to Damascus and visit the glorious Ummayad Mosque, a former church that is allegedly the site of St. John the Baptist's tomb.
In Syria, there is no rancor between Catholic and Orthodox Christians. As a minority of 10 percent in an overwhelmingly Muslim country, they have long been made peace with one another.