Church and state in Czechoslovakia spar over role of two saints.The two men who converted Slavs to Christianity in the 9th century are at the center of controversy in Czechoslovakia: in part, it has been a sharp reminder to the state that the church is winning increasing support from nation's frustrated youth.

A bitter tussle for the ``souls'' of two 9th-century Slavic scholars and saints is going on between the Roman Catholic Church and the communist state in Czechoslovakia. It began in February when Pope John Paul II initiated a year-long observance of the 1,100th anniversary of the death of St. Methodius. The observance also honored his brother Cyril, who passed on a few years later.

Between them, these brothers converted the Slav tribes of middle and southeastern Europe to Christianity, gave them an alphabet, and founded their literary culture.

The latter contributions are not disputed by the communists. Indeed, the Cyrillic alphabet is still used in Russia, Bulgaria, and the republics of Serbia and Macedonia.

But the hard-line regime that displaced the reformers of the ill-fated Prague Spring of 1968 has since then displayed the most uncompromisingly antireligious attitudes of any Soviet-bloc country.

It has made a major issue of the brothers' missionary, evangelizing role -- an aspect of their lives that the church has naturally stressed in its commemorations.

President Gustav Husak's government says the Czechoslovak church leaders, and behind them the Vatican are misusing the celebrations by turning them to ideological and political ends that, it says, are in line with the Vatican's so-called ``Eastern policy,'' which the Czechs say is aimed at destabilizing the communist states of Eastern Europe.

The Pope himself has not been spared from attack. When the Czechoslovak primate, Frantisek Cardinal Tomasek, invited him last year to attend part of this year's celebrations, the Prague authorities at once let it be known that, in the absence of diplomatic relations with the Vatican, such a visit could only be a private one. It was another formula for saying ``no way.''

The onset of the commemoration period -- for Methodius in April and then for the brothers' joint name day in July -- set off a new wave of news media propaganda against the church.

Party doctrinaires set up Marxist guidelines -- which are being backed by books, exhibitions, and lectures in universities and schools -- to counter the religious view with the ``correct'' materialist interpretation of the brothers' contribution to early Czech and Slovak statehood.

In April, at the first ceremony, 7,000 Roman Catholics gathered inside and outside the church in the Moravian village of Velehrad, where Methodius died. Many among them were priests who were proscribed by the state from public performance of their office.

For the authorities it was a sharp reminder of the extent to which the church, under Czechoslovakia's generally hard-line regime, has in recent years won increasing support from the frustrated younger generation and with more politically minded dissenters, such as those identified with Charter 77, a human-rights group.

Cyril and Methodius ``belong'' to Yugoslavia and Bulgaria as well as to Czechoslovakia, and there is currently a private spat between Belgrade and Sofia over what language the brothers really taught.

Sofia says it was ``old Bulgarian'' -- in line with its claim that present-day Macedonia is a Yugoslav invention and that a Macedonian nation does not exist.

Not so, say the Serbs and (Yugoslavia's) Macedonians -- it was the ``Macedonian language'' as spoken in the early Salonika region.

But in Bulgaria and Yugoslavia, the governments and their respective Orthodox churches are working together rather than quarreling over the significance of this Slavic anniversary.

In each country, the Orthodox Church is a national church, presenting the secular authority with none of the problems created by the Roman Catholic Church's international links.

In Czechoslovakia, the Husak regime's anxiety about the Catholic Church has been evident ever since Poland's Karol Cardinal Wojtyla became Pope in 1978, even though the church in Czechoslovakia commands nothing like the nationwide hold it has in Poland.

A round of talks between the Prague government and Vatican officials last year failed to ease tensions, and the controversy over Cyril and Methodius has introduced new strains. And the Vatican has announced its secretary of state, Agostino Cardinal Casaroli, will represent the Pope in next month's Czechoslovak celebrations.

Although the Roman Catholic Church in Poland and Hungary has its problems with the government, these are small alongside the Draconian controls under which it must function in Czechoslovakia.

For 20 years, 10 of 13 Czechoslovak dioceses have been without bishops, because the government has rejected the church's selections. Only 3 in 4 of more than 4,000 parishes have priests, because the government limits entry to the training colleges. Thus, some priests have to say mass in a dozen scattered village churches on a single Sunday.

Priests may be prosecuted and effectively prohibited by the state from taking part in unlicensed religious activity, public or private. Some 500 are currently banned in this way, according to church authorities.

The number of priests imprisoned in recent years has rarely seemed to be fewer than 100. Often they had done nothing more than lead religious practice in their own or other private homes. And the number of such arrests is increasing, as repression and propaganda turn more young people toward religion, rather than away from it.

In fact, after years of intensive campaigning, communist spokesmen are compelled to admit that faith dies hard.

In Slovakia, with its centuries of devout Catholic tradition, a recent report disclosed that up to 70 percent of children are baptized, despite local party pressures on parents, and that even party members take their children to remote villages for baptism, with the understanding that the priests will make sure the children's names do not appear in the christening registers. 30{et