Try as it will, Poland's Communist Party can't regain its credibility

After nearly three years of crisis in Poland, the ''state of the party'' causes the Communist leadership here almost as much anguish as the state of the stricken economy.

''It is only a symbol,'' a veteran member of the Communist Party remarked ruefully. ''Effective rule of the country is still military.''

There were moments back in 1981 when the party faced what a prominent member of the Politburo, Kazimierz Barcikowski, has called ''a real threat of disintegration.''

The immediate danger then was averted. The party was given a more democratic structure. Its methods of operation were adapted more closely to society's needs.

But tensions quickly built up again. And at the end of 1981 the imposition of martial law relegated the party to playing second fiddle to military rule.

Today, martial law has been suspended for just over four months. But the party still shows only minor signs of recovery.

''Many basic organizations are still in the doldrums and on the defensive,'' Mr. Barcikowski said in a recent, remarkably candid interview with a Polish newspaper. He was clearly referring to the party's inability to carry popular conviction at its regional and local levels.

In February, Gen. Wojciech Jaruzelski, the party leader, admitted in effect that efforts to counter the mood of apathy and skepticism among much of the party rank and file had yet to make a significant impact.

Party members must be more militant, he told a series of regional activist meetings. They must show more ''aggressiveness'' in their political work. It was their task, he said, to ''stamp the influence of the party on every aspect of Polish life.''

Conversations with ordinary Poles, including some who belong to the party, however, confirm this observer's impression that the Communist Party still has not regained any real standing in the public eye.

In theory, the Military Council that had full powers during martial law has withdrawn into the background. It is rarely mentioned now.

But the council has not been formally disbanded. And it will not be until the state of emergency is lifted completely, including the continued military supervision in all key economic and industrial centers. Moreover, members of the council still occupy key posts in government.

Communist Party membership, meanwhile, stands at about 2.4 million, according to the latest official figures, compared with nearly 3.2 million before the crisis erupted in August 1980. This represents a loss of some 760,000 members, most of whom chose to resign or became disenchanted and simply dropped out. Although no figures have been disclosed, recruiting is clearly minimal.

The present party strength is said to be sufficient, and no longer declining. There is no hurry to draw in more members.

Neither is there any hurry from people outside to join, as there had been in the euphoric days of the early 1970s. Mr. Barcikowski suggested in his recent interview that the reform program of the 1981 party congress had never really reached down to the grass roots or been convincing to rank-and-file workers.

The aim then was to achieve wide-ranging ''renewal'' in all walks of Polish life. The word renewal is still heard, but much less in its original, reformist sense. For too many Poles - party members as well - the word lost its real meaning under the impact of military rule.

Disillusion with the party is reflected in the changes in its social makeup. In today's ''workers' party,'' actual worker membership has declined to only 30 percent - much lower than anywhere else in the Communist bloc. Only percentages of white-collar workers and pensioners have risen.

The 1981 congress set up a commission to analyze the party's periodic defeats and crises since World War II.

The report was to have been completed by last summer and made public in its entirety. But it still will not be ready for two more months. And when it is finally finished, it is unlikely to be made fully public, Prof. Hieronim Kubiak, a Politburo member and head of the commission, told the weekly magazine Polityka last month.

This suggests the existence of strong conflicts of view in drafting a potentially embarrassing document.

It is already public knowledge that there are severe strains within the party leadership between its relatively few moderate and quasi-liberal members and the harder line faction that is still demanding tougher measures against any kind of opposition.

Writing last month in Trybuna Ludu, the head of the government's public-opinion research center, Col. Stanislaw Kwiatkowski, argued that when martial law is finally removed, the authorities must replace force with persuasion. The latter, he said, was a process in which there could be no room for an ''ideological gendarmerie'' (the hard-liners) if public support was to be won.

There came immediate reaction from a former ranking, ideological official who said the colonel overlooked the danger from the ''liberal'' wing of the party.

It was another reminder that, while moderates are talking of a pluralist coalition model and an ''intra-system, self-opposition'' in the party itself, a large hard core of the orthodox ''old guard'' has not given up.

For the moderates, the problem still is one of establishing a ''center'' within the party and among the general public that is strong enough to meet an attack from the hard-liners.

''One thing is certain,'' Mr. Barcikowski said of the roller coaster times of 1981, ''we were in trouble, in big trouble . . . and there really were moments when the specter of defeat looked us straight in the face.''

The trouble is that the party leaders have yet to find a way to rebuild the party's credibility within its own ranks and among the public at large. They have yet to discover how to reassert the party's supposed ''leading role'' in society.