EUROPE : Pope Hits the Road Again : John Paul heads for Spain, where secular freedoms challenge Catholicism.

John Paul II, the Pope who never stops, goes back on the road again today, this time to nearby Spain for a firsthand view of a typically European struggle between old-time Catholicism and new-found secular freedoms.

For the 73-year-old pontiff, the trip, his fourth to Spain and his 59th abroad since 1978, is a milestone of sorts. It is just a year since John Paul, a pain in his belly, grimly endured an exhausting week’s visit to Angola. In July, he had an intestinal tumor removed.

Today John Paul embarks on a six-day Spanish visit with a more intense workload than in Angola. Between the time he arrives in Seville this morning and Sunday night, the Pope is scheduled to make eight public speeches at as many events.

At the Vatican, too, John Paul, who got a clean bill of health on a six-month postoperative checkup, is as busy as ever with meetings, audiences and speeches. On the eve of hisdeparture, he received Alija Izetbegovic, the Muslim president of Bosnia-Herzegovina,at the Vatican Friday.

What takes John Paul to the blinding white summer heat of Andalusia is an international Eucharistic Congress there, which he will close Sunday in Seville. He swings through coastal southern Spain Monday.

In Madrid on Tuesday, the Pope will inaugurate a new cathedral, a century in the making, and canonize a 19th-Century Spanish priest.

Along the way, John Paul will sternly lecture the citizens of a modern democracy, which, he complained in 1991, had fallen into the grip of “neo-paganism.”

About 95% of the 39 million Spaniards are Catholics. But, like many West European Catholics, most Spaniards nowadays turn to their church principally for rites of passage: baptisms, weddings and funerals. Only 25% regularly go to Mass every week, one recent poll said.

A dramatic decline in the Spanish priesthood mirrors the continental decline, according to church figures. In 1960, about 23,000 young Spaniards were studying for the priesthood. Today there are barely 2,000 seminarians around the country, and the average Spanish priest is older than 50.

In his remarks to Spaniards, aides say the Pope will try to bridge the gap between traditional teachings and modern practices in a young democracy where sexual freedom is an accepted fact of life and church-proscribed practices such as abortion and divorce are legal and available.

Although the Establishment church was long associated with the four-decade dictatorship of Generalissimo Francisco Franco, individual priests later became some of his most significant opponents. Still, in the democratic aftermath of Franco’s death in 1975, church influence has waned steadily.

In the past decade, particularly, there has been a marked distancing between religion and politics under the rule of socialist Prime Minister Felipe Gonzalez. He defeated a conservative challenger in elections last Sunday to win a fourth term in office--to the despair of some senior Spanish churchmen.

The Pope’s meeting in Madrid with Gonzalez will be a model of decorum, but it would not surprise anybody if John Paul comes out swinging everywhere else against what he sees as declining Spanish moral standards.

John Paul hoped the defeat of communism in Eastern Europe would generate a rebirth of spiritual consciousness in Catholic countries of Western Europe. He has been disappointed: Eastern Europe has proved less interested in asserting the bedrock moral integrity that survived decades of communism than in importing Western materialism.