He won the battle against Communism but not the fight against modernity

Once fear of hell and hope of heaven are lost, no church which John Paul II would recognise could long survive

Tu es Petrus et super hanc petram aedificabo ecclesiam meam (Thou art Peter and upon this rock I will build my church). John Paul II, one of the most important popes since St Peter, was a Petrine character. He was a rock on which a citadel could stand; a rock upon which faith's enemies would split asunder.

Cometh the hour, cometh the man. John Paul II became Pope at the right moment, from the right background. Poland's modern history had been a crucifixion: mass murder, the destruction of cities, attempts to eradicate the Polish nation. Everything in Poland was broken, except spirit and faith. There was always a resurrection.

John Paul II was a symbol of his countrymen's sufferings, and their strength. His appointment alarmed Yuri Andropov, the head of the KGB who was shortly to become the leader of the Soviet Union. Some people thought that Andropov was not merely reacting out of political calculation and that under the Communist carapace there was a residue of religiosity which led him to wonder whether God might be tapping history on the shoulder.

It was both understandable and appropriate that the KGB should have plotted to assassinate the Pope. The script needed a Judas. The wounding and the hatred only magnified John Paul's power, and his charity. Confronted by good, evil shrivelled.

Historians will always argue as to the Pope's exact role in the fall of the Soviet empire. But on one point, we can be certain. John Paul II refuted Stalin. How many divisions has the Pope? If you are the servant of the servants of a Kingdom not of this world, you do not need divisions and none can stand against you.

John Paul II ranks with Churchill, Reagan, Roosevelt and Thatcher: the five greatest figures of the 20th century. But the Pope would never have seen his role in political terms. I have heard a number of people who had the privilege of meeting him, and they all said the same. He was a wonderful pastor. There was awesome authority, but there was also a twinkle in his eye. Above all, there was a warmth and a profound humanity. This was not some austere figure to whom the disciplines and rigidities of the priestly vocation had come easily. He had achieved serenity, but not without struggle and sacrifice, and never losing sympathy for those who found the struggle hard. All this was expressed in his face, which looked like rock carved into love.

The Pope believed that when the Church is embattled, the faithful need exemplars. At a time when sophisticated churchmen were beginning to bracket sainthood with superstition, he urged onward the creation of new saints. It is to be hoped that the practice will continue, at least until John Paul II's heroic life and heroic faith have been acknowledged by a rapid path to sainthood.

This does not mean that he has left the Church on an easy path. However much they admired the man, most Western liberals - including many Catholics - deplored his views. As soon as the reticences of mourning are over, there will be calls for a more accommodating route. As John Paul II appointed almost all the cardinals who will choose his successor, it would seem likely that the new pope would have similar opinions without the majestic personality. If so, the Catholic Church in Europe could rapidly become ungovernable.

There is a basic difficulty. The Pope was a Christian. His theology and his teaching were rooted in Scripture and in tradition. However difficult it may be to live up to the doctrines, it is hard to see how any professed Catholic could challenge them.

One would have thought that the devout ought to share Andropov's view, with more enthusiasm. They might indeed ask themselves whether it was mere chance that led the Pope to the Vatican just as the Aids virus was about to strike the West. The God of the Old Testament would have been perfectly capable of sending a plague to reinforce the warnings of a prophet.

Yet few Catholics think like that today. Many are prepared not only to challenge the Church's teachings but to treat them with a casual disregard.

There is a simple explanation. They no longer believe, or at least, not in a way that their forbears would have recognised. What proportion of European Catholics now believe in an afterlife? Even among those who might entertain a vague notion of eternal celestial choir practice, how many believe in hell? Until recently, most people's faith had its roots in fear of the four last things: death, judgement, heaven and hell. If the final three have lost their potency, there only remains death, and the modern response to the fear of death is to enjoy oneself as much as possible in the interim, on the assumption that life is not a dress rehearsal but a first and final performance. As in most contemporary theatrical performances, there is likely to be a lot of sex, and not in a form compatible with orthodox Catholicism.

Once fear of hell and hope of heaven have both been lost; once God becomes just something out there - there must be something, mustn't there - once millennia of canon law and dogma declines into a mish-mash of ethical platitudes, a lobotomised version of the Sermon on the Mount, no church which John Paul II would recognise could long survive. That is why the Pope regarded Godless Capitalism as a graver threat than Godless Communism. The Church can survive and even strengthen under Communism. But can it resist consumerism and the subtle martyrdom of the shopping mall?

That is a problem which the Pope has bequeathed to his successor. It may be that just as John Paul II brought a fresh geographical perspective, so will the new pope. Though the subversions of secularism and liberalism may lead European clerics to advocate appeasement, such frailty is not widely shared in Latin America or in Africa. It could be that the cardinals will return to Italy for the new pope. If so, that might become a de facto precedent: Italian and non-Italian, turn and turn about. It is perhaps more likely that they will acknowledge the universality of the Church by selecting a non-European.

If that were to happen, the centre of gravity would move away from Europe, as in so many other areas. Rome would still house the Church's bureaucracy and its museums. The Pope would still reside in the Vatican. But the Church's vitality would come from other sources and other continents.

It seems unlikely that these questions will be rapidly resolved. It seems almost inevitable that they will not be resolved in a way which John Paul II would find satisfactory. In the battle against the corrosion of modernity, there is no equivalent of the Berlin Wall.

The Pope may not have won, but he fought the good fight. This was a man who had a numinous quality. His moral inspiration will endure.