Pope John Paul II issued his harshest criticism to date of repressive Latin American governments yesterday, and strongly condemned those leaders who invoke state security to justify violating the rights and dignity of their people.

In an address to the 27-nation Organization of American States, the pope called such security justifications a "sham,, and put his seal of approval on members of the Latin clergy who actively defend human rights.

Yesterday's speech was far more pointed than any John Paul delivered during his five-day trip to Mexico last January. At that time, to the applause of conservative sectors of the Latin church and bitter disappointment of Catholic activists, the Pope directed the clergy to stay out of politics and stick to evangelization.

The subject is one of the most controversial in Latin America, where 95 percent of the population claims at least nominal ties to the powerful Catholic Church. The Pope's Mexico trip was occasioned by a Latin bishops' conference that became a showdown between traditionalists and proponents of the Latin-born "theology of liberation" which holds that a priests' duty includes the active protection of the human and civil, as well as the spiritual, rights of his parishioners.

Although he spoke of a more equitable economic distribution in Mexico, many activist Catholics felt John Paul's words there did not begin to address the real problems in a part of the world where any act on behalf of human rights is branded "political" and priests are regularly persecuted as subversives.

In his speech to the OAS, however, the pope concentrated almost exclusively on human rights. Even a call for disarmament, which he has made throughout his U.S. visit, was put in terms of what he called mistaken beliefs that a weapons buildup "is sufficient to ensure internal peace in the single countries."

Referring to "the painful experience of. . .my own country, Poland," the pope said he recognized the importance of protecting national sovereignty.

Most of Latin America's authoriatarian governments are rightist and military dominated. They see themselves as severely threatened by both international and domestic communism, and justify repression on grounds protecting the state. Many have long been accused of torture, and even murder, committed in the name of security.

"However, John Paul cautioned, while such difficulties and experiences can at times call for exceptional measures. . .they never, never justify any attack on the inviolable dignity of the human person and on the authentic rights that protect this dignity.

"If certain ideologies and certain ways of interpreting this legitimate concern for national security were to result in subjugating to the State man and his rights and dignity," he said, "they would to that extent cease to be human and would be unable to claim without gross deception any Christian reference."

Social organization, John Paul said, "is at the service of man, not vice versa. . .a security in which the poeples no longer feel involved, because it no longer protects them in their very humanity, is only a sham; as it grows more and more rigid, it will show symptoms of increasing weakness and rapidly approaching ruin."

Rather than repress dissatisfaction and legitimate protest with force, the Pope called on governments in the Western Hemisphere to direct their efforts toward the "welfare of man."

"All that you do for the human person," he said, "will halt violence and the threats of subversion and destabilization."

The Holy See, he said, "will always be happy to make its own contribution ot this work." At the same time, "the local Churches in the Americas will do the same. . ."

Rather than work against their governments, the pope said, local clergy could, "by advancing the human person and his or her dignity and rights. . .serve the earthly city, its cohesion and its lawful authorities."

During his Mexico visit, John Paul addressed himself to the development of Christian values as a means for solving problems and ending conflict in Latin America. Yesterday, however, he reversed the syllogism somewhat by calling on governments to respect the rights of their citizens so that they and the church can devote themselves to Christianity.

"The more all citizens are able to exercise habitually their freedoms in the life of the nation, the more readily will the Christian communities be able to dedicate themselves to the central task of evangelization.

It is unclear why John Paul decided to change the emphasis of his message to that part of the world with a great concentration of Catholics than any other.

As the pontiff himself noted yesterday, he was "amazed at the enthusiasm, spontaneity and joy of living" of the people in Mexico, and some observers speculated that the pope also came away from that trip with a different sense of Latin America's problems than he had on arrival.

At the same time, the Pope has received a number Latin clergymen in the Vatican in the interim, including the archbishops of Managua, Nicaragua and San Salvador, El Salvador -- both liberal activists who have been the objects of government persecution.