Having just spent a month in East Germany, Poland, the Soviet Union and Hungary, I came home with this big question: What will Mikhail Gorbachev do, indeed what can he do, about Poland?

Poland represents rebellion -- yesterday open rebellion, today sullen rebellion. Solidarity, the amazing labor movement, is pretty well smashed, with some of the reforms it advocated being carried out by the new official trade unions. But the spirit behind Solidarity is very much alive. The Roman Catholic Church with which it is entwined seems both more powerful and more defiant than ever. Today's communist regime in Warsaw is a military junta, but it has less contol over the population than that exercised by many a junta in the Third World.

The Polish church, before Solidarity, worried about "captive minds" among the young, but no longer. Now, says a former Solidarity activist who reflects the views of Cardinal Josef Glemp, the problem is what to tell the public about the future because people have no sense of having any influence on things beyond their private sphere.

Despair has brought an increase in alcoholism and, most recently, in drug addiction to a substance made from local poppies. Church sources estimate that already some 50,000 young people have been "lost" to such drugs, with another 200,000 to 300,000 using them.

The economy is described by many as in ruins. Corruption is rampant. The American dollar bill is openly a key currency on the streets of Warsaw and other cities. Cabdrivers accept dollars willingly, and waiters in the official tourist hotels openly suggest that you pay your bill in dollars, not zlotys, a transaction by which they, like the cabbies make a fine profit. The official rate when we were there was around 134 zlotys to the dollar, but the street rate varied from 500 to 800 or more, depending on what kind of bills you proffer and how well you bargain.

The government simply condones all this; it seems hopeless to fight it, and besides it helps meet part of Poland's desperate need for hard currency. These black-marketeers, we heard, use their big profits to buy such scarce items as autos or apartments for their children, the latter costing as much as a million zlotys. Traffic cops have a reputation for taking payoffs on the spot for minor infractions.

But all this pales in significance next to the dynamism, vibrancy and influence of the Catholic Church. Pope John Paul II may seem to many in America to be very conservative, but to the Russians he is a radical threat, while in his native Poland he is the supreme symbol of hope.

To go on a Sunday morning to mass in Warsaw's St. John's Cathedral is to sense this. To stand outside in the jammed street, listening to the service in Polish over loudspeakers is unforgettable. To see a few blocks away the waiting militia, their water-cannon vehicles and paddy wagons at the ready, adds to the tension.

To know that the priest this day is using the 50th anniversary of the death of Marshal Josef Pilsudski, the Polish patriot who fought both the czar's troops and the Red Army, as a vehicle for a sermon on patriotism is to realize how effectively religion can be used for political purposes.

To hear the mass end with the solemn singing of the ancient verses of "God, give us back our homeland" as every man, woman and child thrusts forward the fingers of their right hands in the V for victory sign is a spine-tingling experience.

Then to go across the city to a crowded mass at the modest church of Father Jerzy Popieluszko, the young priest murdered by the state's security apparatchiks and whose grave in his churchyard has become a hallowed shrine, is to feel again the resistance, the defiance of Poland to the Soviet will.

From the train windows all across Poland, from the East German border to the Soviet border, is a nearly continuous panorama of small privately owned farms. The farmer holds the plow, the wife handles the reins of the family horse and children walk behind dropping seed after seed. There are few tractors for these farmers, more for the small amount of acreage that is collectivized. But the private land, like the church, is fiercely defended, and efforts to change the system, so often urged by Moscow, get nowhere.

Premier Wojciech Jaruzelski, the man who runs the country to the degree that any one person does, is, as one knowledgeable Pole described him, locked in a Catch-22 situation with the Russians, the church and the public. Diplomats say he sees himself as a Polish gentleman and a patriot.

At this spring's Warsaw Pact meeting in his capital, which brought Gorbachev there for the first time as head man, the ramrod-straight Polish general insisted on a one-on-one meeting rather than, as the Russians were said to have suggested, a Gorbachev meeting with the entire Politburo. To show that he got his way, Jaruzelski later publicly announced that he had "reported" to the Politburo on his talk with Gorbachev.

In Moscow they tell you that the Polish problem is "manageable." When I listed all the negatives of church strength, private farms, a broken-down economy, public dislike of the Russians and a form of military rule violating Marxist-Leninist precepts, a Soviet official replied only that it was "not quite that gloomy."

Stalemate perhaps best describes the current state of Soviet-Polish relations. To change that certainly will be one of Gorbachev's toughest tasks, should be decide to try.