Pope John Paul II called on the Latin American clergy today to work for social justice through evangelization and building the traditional church rather than through political activity.

In what many observers interpreted as a severe criticism of the so-called "theology of liberation" practiced by activist Latin priests, the pope said Jesus "does not accept the position" of those mixing matters of God with "political attitudes."

"The idea of Christ as a political figure does not tally with the church's catechesis," or teachings, he declared.

The pope's address, billea by the Vatican as the most important of his week-long trip to Latin America, was delivered to the opening session of the Latin bishops' conference, held in a seminary here.

It followed a three-hour drive to Puebla -- Mexico's fourth largest city, with a population of 800,000 -- from the capital 65 miles away.

Despite the heat of the day and the difficulty of the climb to the high-altitude highway, virtually the entire route was lined several layers thick with Mexican villagers, some of whom traveled miles to perch on the hillside and view the papal motorcade.

John Paul's long-awaited speech to the closed conference session is sure to have a strong impact on its deliberations over the next two weeks and on the future course of the Catholic Church in Latin America. The conference is the first held since 1968, when the bishops gathered in Medellin, Colombia, to develop guidelines for putting in practice the Vatican II social doctrines espoused by Pope John XXIII.

Much has changed in Latin America since the Medellin conference If anything, the social and economic inequities are more extreme and the vast majority of Latin countries are now ruled by right-wing, often repressive, governments.

At the same time, the Latin clergy has sharply divided on the issues of how and how far the church should help support the poor. The "liberation" theologists, who range in ideology from progrestive moderates to a fringe of outright Marxists, believe the church can no longer help its people simply by making them good Christians, but must take an active role in changing institutions.

Thus in countries like El Salvador and, to a lesser extent, Nicaragua, the church is at the vanguard to denounce repression and organize opposition. Bishops in Brazil and Chile, and recently in Argentina, have denounced their military governments

A third, and more conservative, faction of the Latin clergy has criticized both the moderates and the Marxists for deviating from the traditional evangelical and pastoral roles of the priesthood.

Today, while offering understanding for the problems of the poor, John Paul came down squarely with the conservatives.

The pope dealt with most of Latin America's pressing social issues. He exhorted the bishops to "make every effort to ensure that there is pastoral care for the families," including fending off threats from "campaigns in favor of divorce... the use of contraceptive practices and of abortion, which destroy society."

"A true evangelical commitment," he said," is a commitment to the most needy. In fidelity to this commitment, the church wishes to stay free with regard to competing systems, in order to opt only for man."

While John Paul's doctrinal traditionalism and strong anticommunism have been a topic of much discussion in the Latin clergy, the weight of his criticism of the more liberal and "secularized" priests dashed many lingering liberal hopes and will likely provide encouragement for conservative church leaders.

"How can he tell us to evangeline," complained one Catholic priest who came to observe the conference, "when 90 percent of Latin Americans are already practicing Catholics and the majority poor see that it hasn't done much for them?"

He referred to "the growing wealth of a few [and] the growing poverty of the masses." He spoke of a "defense of human rights" and acts "in favor of brotherhood, justice and peace, against all forms of domination, slavery, discrimination, violence, attacks on religious liberty and aggression against man, and whatever attacks life."

But the unmistakable thrust of his talk, repeated over and over again, was that the mission of the church is evangelization and not politics: that true justice will be achieved when "Christian principles are instilled in all men."

Police cleared the road to Puebla, a four-lane divided highway through mountain forests and high-altitude passes, at 3 a.m. today. By midnight Saturday, police cars were positioned at 100-yard intervals all along the road, warning anyone who stopped that the toll gates would soon be closed.

After standing nearly three hours in the open vehicle, John Paul was sunburned despite his broad brimmed hat and he appeared fatigued.

As the motorcade pulled into the black gates of the seminary, John Paul gave a brief wave to a youthful drum and bugle corps assembled to welcome him, hitched up the wilted skirt of his white garment and disappeared into the building.

Within minutes he reappeared at a front balcony of the seminary dressed in gold robes and miter, and he begin the Sunday mass.

The sight of the regally dressed pope, in front of wide scarlet hangings on the high balcony, was awesome.

The context of the homily, like those delivered in private to groups of nuns and priests yesterday, left liberal Latin clerics disappointed and most others questioning. Its theme was "the family" and the instruction was clear: the church's work in Latin America is the promotion of spiritual growth through the family.

Last Thursday, on the evening before the pope's arrival in Mexico, a gathering of 35 activist groups in one of Mexico City's poorest barrios composed an open letter to the pope.

"You've come to know our pains, not listen to applause," they told the pontiff. "You were a worker. You know how things are."

In efforts to help Latin Ameria's poor, the group told John Paul: "You will not go alone."

"We are here, disposed to work so that life does not continue to be so sad for so many of our brothers," they wrote.