Pope John Paul II received a tumultuous welcome in Mexico, but he arrives at a time when Marxist priests in Latin America have clashed openly with their superiors.
The conflict is over the direction the church will take. Should the church be on the side of social reform, even violent revolution? Or should the church hue to traditional spiritual goals?
There's not much middle ground down there.
Hernan Cortes, the first Catholic to come to Mexico, came as a conqueror and ruled by force of arms. Pope John Paul II is the latest Catholic to come here. He has come, he says, as a traveler of peace and love. He will need all his skills as a peacemaker, for the church here is at war with itself.
But there's no doubt he has already conquered the hearts of the Mexican people. So this is our cover story this week, and it begins with some impressions.
What you remember is the people, millions and millions of people - people shouting and crying and laughing and waving, and people praying and singing all over Mexico City, everywhere he was. The sight and the sound of it filled the senses and splashed forever into your memory.
One man looked at him and said: "Mano, el Papa es joven" - "But the Pope is so young."
The Popes these people have always known were very old, or very stern, or very sad. This Pope was smiling and strong.
And his colors on the vestments he wore were their colors: the white of Veracruz, and the gold of Aztecs, and blood-red of the revolutions.
Not old or sad or stern this Pope, but human, benevolent. He seemed to know all your dark sins and forgive you for them. That is what you remember from this weekend in Mexico - all the faces, the millions and millions of faces, and his face, and the face of one little girl.
On a Sunday morning at mass, Armadilla Virasteroz Torez, age four, has come to be introduced to her church and her God. It is a custom among the poor. Their children so often die young. So when a little girl reaches the age of four, it is a time for thanksgiving. Armadilla is already a survivor with a future.
From now on the church will be the marrow of her life, as it is for her family, as it is for 300 million Roman Catholics in Latin America - almost half the Catholics in the world.
The people of this Church of Our Lady of San Miguel in the slums near Mexico City's airport came here from the countryside because life is a little better. The church is their touchstone, their solace in grief, their promise of something better in the next life. But the church never offered them much hope in this life, until now.
Catholicism has had a split personality in Latin America since the first Spanish missionaries landed with Cortes in Mexico four centuries ago. The missionaries protected the natives, tended to them, Christianized them; but the church became rich, conservative, an instrument of the soldiers and the wealthy.
Eventually, Mexico, for one, had enough. In one revolution after another, it stripped the church of its lands and its power, and persecuted the clergy. Mexico does not have relations with the Vatican. It does not allow priests and nuns to wear clerical garb on the streets. Mexico, officially, is one of the most secular nations in the free world.
Unofficially, Mexico is one of the most devout.
The citizen of every parish is the parish priest, like Father Cesar Costunada in the parish just around the corner. Like so many of his fellow priests, he has begun to spend less time in church and more in the neighborhoods.
"We decided to draw up a plan to make life better here," he told Threlkeld "We decided the people wanted more family counseling, more church activities. Then we asked the people what they wanted. It wasn't that at all. They wanted the streets paved, so we got some streets paved. They wanted a cooperative grocery, so now we have that. They wanted a doctor, so now we have a doctor." Father Costunada has become a part-time priest and a full-time ward boss and social reformer.
It is a communion of radical change, the clergy and their faithful struggling to make things better in the here-and-now. It is called the "theology of liberation," and it is both a promise and a problem. In Mexico the priests and their poor are fighting a sluggish bureaucracy.
In El Salvador, Chile, Argentina, or in Nicaragua recently, it has become a sometimes violent struggle with savage dictatorships. In the last ten years in Latin America, more than 800 priests have been arrested, expelled, tortured, murdered or killed in combat practicing the theology of liberation.
And so now there is a struggle within the church over who is to lead the faithful, and where.
Conservative bishops, conservatives in the Vatican, think they are losing control of the church. They are determined to get it back at the Bishops' Conference in Puebla. They want the priests to spread the gospel and stop spreading revolution, and they want the Pope to help them by rapping some knuckles. But the liberationists are claiming a higher authority. Father Luis Delvia of Mexico City is one of the leaders of the movement.
"The last ten years of Latin American history have shown that those who chose to fight the system, those who chose to live with human dignity, have been persecuted," he said. "This is the same thing that happened to Jesus Christ. We may be a minority in the church, but we are the one part of the church that is alive."
It is a new catechism of conflict that troubles the church here. The questions are just as fundamental, but not so easy to answer, as the ancient litany they teach the children: Who best obeys the words of Christ? Those clergy who follow his mandate to feed the hungry and shelter the homeless whatever the sacrifice, or those who render unto Caesar? Questions to perplex - well, to perplex even a Pope.
At the Basilica of the Virgin of Guadaloupe, Mexico's most holy shrine, the Pope spoke of the problems in the church here, but only gently. He did not mention those priests who have become Marxists. He said nothing of those bishops who have chosen to live and let live with the dictators. Instead, he prayed to the Virgin to guide the church according to the words of Christ. Which words, he did not say.
Perhaps if the Pope has a sermon to give about the theology of liberation, it will come later when he meets the bishops. Or perhaps he will stand aside and let the church here find it own way.
He bears the names of three Popes who have died. He must know that change is in the natural order of things. He knows that Popes don't rule the church any more; they are teachers who lead by example. Certainly, he will pray for the future of his church, for the future of his people and for the future of a little girl.