Poland's Roman Catholic Church, as so often before in its 1,000-year history, has emerged as the main national rallying point following the imposition of martial law and the suspension of the independent trade union federation Solidarity.

The church is the sole independent institution of any stature in the country not to have been smothered by the draconian new measures. With the Polish-born pope in Rome and the allegiance of over 80 percent of the population, it was too strong an opponent for the military authorities even to attempt to move against.

The result is that, a month after the declaration of martial law, the church is seen as the representative of Polish society in negotiations with the government. Polish bishops, supported by Pope John Paul II, have set as their aim the ending of martial law as swiftly as possible and the restoration of democratic reforms, including the existence of an independent trade-union movement.

There appears to be some disagreement within the church hierarchy, however, over how fast and how strongly to push for the realization of these goals. The uncertainty has been reflected in public statements by the primate of Poland, Archbishop Jozef Glemp, who has alternated between expressions of repugnance at martial law and appeals for calm and the avoidance of violence.

His dilemma is that, although he is bitterly opposed to the suspension of basic freedoms in Poland, he does not want to encourage open resistance to the authorities, which he fears could result in widespread bloodshed and possibly even a Soviet invasion.

In a sermon last week, he echoed the anguished plea of his predecessor, Cardinal Stefan Wyszynski: "Sometimes it is more heroic to live for the nation than to die for it." On another occasion, Glemp described the martial law as "evil," but added that the church was powerless to struggle against it.

Some lower-level priests have been much more forthright in their condemnation of the authorities, despite strict instructions from their superiors not to make political statements. At one Warsaw church last Sunday, the priest denounced "godless Communists" in vitriolic terms in his sermon. He depicted martial law as the work of a band of traitors betraying the nation to a foreign power.

At another church, the priest told a large congregation of indignities suffered at the hand of the government by the Black Madonna of Czestochowa, the icon that bears the most sacred image of Polish Catholicism. He described how a copy of the madonna, known as the Queen of Poland, had been locked away to prevent it from touring the country during celebrations to mark the millennium of Polish statehood in 1966.

"The church guards managed to save the frame, so it toured the country alone and drew vast crowds," the priest recalled.

Such incidents help explain the present strength of the Roman Catholic Church in Poland. They have recurred throughout the nation's history and have later been embellished by popular imagination. In addition, the church won enormous prestige as a result of its opposition to the Nazi occupation during World War II and Stalinist terror in the late 1940s and early 1950s.

Today the church exercises a kind of elemental hold over most Poles who see it as a repository of national interests. It is as if, at times of grave danger, the church represents the one sure reference point for a nation battered by the storms of history and the geographical misfortune of being situated between Russia and Germany.

It was, therefore, natural that the first public act of many Poles following the declaration of martial law on Sunday, Dec. 13, was to go to church. They knelt in prayer before pictures of the Black Madonna, a badge of which was habituallym that includes the phrase: "Oh, Lord, please bless our free fatherland." Following the declaration of martial law, that became: "Oh, Lord, please return to us a free fatherland."

With the approval of the bishops, many churches have begun organizing a relief operation to assist detained Solidarity activists and their families. Information is collected about where they are being held and packages of food and clothing are delivered to the detainees.

During talks with the government, the church has concentrated on improving living conditions in internment camps and securing the release of some of the detainees. During his meeting last week with the prime minister and martial law chief, Gen. Wojciech Jaruzelski, Glemp is also believed to have expressed concern at the practice of demanding loyalty oaths from many Solidarity sympathizers or threatening them with loss of their jobs unless they resigned from the union.

The primate returned to the same theme during a sermon on Sunday, an indication that he had failed to make much progress with Jaruzelski.

The suspension of Solidarity means that the church is now the only real negotiating partner left for the authorities. The talks have been held in secret and few details have leaked out. In private, however, church sources are pessimistic.

"It's like talking to a tank," said one priest.

The church has also kept communications open with Solidarity leaders, including Walesa, who attends mass regularly.

Some priests have expressed fears that, once the government is confident of its control over the rest of society, it may be tempted to move against the church. They cite the detentions or beatings of some priests, the closure of Catholic newspapers (along with all other independent publications), the suspension of Catholic discussion clubs, and the stopping of regular radio broadcasts of Sunday mass--one of the concessions won by striking workers in August 1980.

Given the church's roots in Polish society, however, it is difficult to see how such a campaign could succeed.

Besides, the Polish church has a powerful protector. Pope John Paul has been following the crisis closely and, in letters to other European leaders, is believed to have added his voice to calls for an end to martial-law rule. Many Poles believe that it was the pope's visit here in 1979 that paved the way for Solidarity's rise a year later.

The pope has already accepted an invitation to return to Poland in August for the 600th anniversary of the installation of the Black Madonna at Jasna Gora. The military authorities still have not indicated whether they will allow the visit to go ahead.

Many Poles are hoping that, if the pope comes, the wheel of Polish history will start revolving again.