Religion, nationalism and authority were the traditional pillars of the old state-societies of Western Europe. Three generations ago it was still a sacrilege to critize them. The church sanctified the national community and legitimated the authority (a monarch or an authoritarian leadership). If one of these pillars had been removed, the entire system would have been weakened. During the last four decades these traditional values have declined simultaneously, at different speeds, in all Western European countries, without a single exception. Decline of Religious Beliefs Over the past 30 years a decline in religious beliefs has been observable in all the European countries. In some the erosion in faith had begun even earlier but it has accelerated to such an extent in recent decades that it has become detectable in opinion surveys held at close intervals, whereas previously it was a matter of more gradual trends charted by historical studies over longish periods. A decline in religious belief among the majority of the population is not incompatible with a revival of faith in small communities. These groups may attract the attention of the media with their sometimes spectacular activities but their relative weight in the population is so slight that they fail to show up in a survey based on representative sampling. This analysis relates to mass trends and disregards minor ones. Religious decline is shown clearly in religious practices, in particular celebrating mass and attending certain services. It is a well-known phenomenon and has long been a subject of study, particularly by the clergy themselves. As the sociologist S. Acquaviva has pointed out, it is practice which first declines, and then the beliefs themselves begin to crumble. Between the two types of decline there is a gap which time has not so far closed or narrowed. There is a strong relationship between the attitude toward the church and the religious feelings of the interviewed people. In eleven countries, the majority do not express full confidence in the ecclesiastical hierarchy, for a variety of reasons that cannot be detailed here. This is one of the most astonishing findings in the surveys on values. It raises an embarrassing question: Which is the real audience of the church in Western Europe? The Netherlands, after having been long divided in confessional compartments, has become one of the most agnostic countries in Europe. Similar trends have been observed in Sweden, Germany and Britain. This paper deals with religious beliefs and only infrequently refers to religious practice, about which there is a wealth of literature in almost all European countries. Suffice to note that the statistics available on attendance at mass, baptisms, marriages and religious burials and so on show clearly that the decline in religious practice measured over the last 40-50 years has steepened in recent years. No one can prove that God exists or does not exist. But sociologically it is possible to show whether God is present in or absent from people's minds. Belief in the existence of God is an observable social fact. The simplifying question Do you believe in God? elicits a massive majority of affirmative answers. But if people are asked to say where they come on a scale of 1 to 10 as regards the importance of God in their lives we see that it is only for a minority that God has very great importance. God is more or less present, or absent, in most people's minds. For the majority, then, belief in God is relative - neither yes nor no. God may be present in the mind at a time of misfortune or absent at a time of happiness. The International Social Survey Programme found a subtle wording for the question on the perception of God by suggesting six different possibilities: (1) I don't believe in God; (2) I don't know whether there is a God and I don't believe there is any way to find out; (3) I don't believe in a personal God but I do believe in a higher power of some kind; (4) I find myself believing in God some of the time but not at others; (5) While I have doubts, I feel that I do believe in God; and (6) I know God really exists and I have no doubts about it. …