The secularisation of Western societies is not a new phenomenon, nor one which has been overlooked by cultural commentators in recent years.
As a leading authority on changing belief systems, and as a director of the World Values Survey over many years, the University of Michigan's Professor Ronald Inglehart has a particular expertise here.
His newly-published book, Religion's Sudden Decline: What's Causing it, and What Comes Next? , describes the sharp decline in religious belief across the world which has recently been recorded.
Drawing upon data from the World Values Survey and the European Values Study collected in over 100 countries between 1981 and 2020, as well as a range of other sources, Inglehart also puts forward his theories about what has caused this shift, and what it will mean in the coming years.
The facts on the ground are clear. When the author and his colleague Professor Pippa Norris of Harvard analysed religious change in 49 countries between 1981 and 2007, they found that most of these countries had become more religious during this time period, thus confounding the expectations of many researchers.
"When these same 49 countries were reexamined in 2020, the trend towards rising religiosity had reversed itself," the author explains. People in "only six countries showed net gains in religiosity, one showed no significant change; and the publics of 42 countries had become less religious from 2007 to 2020."
The data also shows that far from being the exception to the rule about wealthy, advanced societies inevitably becoming irreligious, the United States "has been secularising more rapidly than any other country for which we have data."
Inglehart describes the various forms of secularisation theory which have been put forward over the years: the belief that religion would decline as scientific knowledge increased, the theory that established churches would become complacent and the theory that the diminishing importance of religious institutions simply reflected a change to a more individualistic form of faith.
He and the aforementioned Norris had previously put forward a separate theory in which they suggested that the greater security of modern life - thanks to industrialisation, widespread affluence and reduced rates of conflict - was reducing the need for the kind of psychological support offered by a religious belief system.
As well as this, Inglehart maintains that secularisation has been accelerated by a departure from what he calls the "pro-fertility norms" of traditional religions to the "individual-choice norms supporting gender equality and tolerance of divorce, abortion and homosexuality."
The dominance of these values - particularly among the young - is pushing more and more people away from religion, and rapidly transforming societies.
Many outside observers have, for example, expressed puzzlement about the sudden emergence of Ireland as a bastion of social liberalism.
The process which the author outlines has happened very quickly in Ireland, and the pace of change is accelerating elsewhere too.
"[T]hough secularisation normally occurs at the pace of intergenerational population replacement, it can reach a tipping point where the dominant opinion shifts, and the forces of conformism and social desirability start to favour the outlook they once opposed - producing rapid cultural change. Younger and better-educated groups in high-income countries have reached this point," Inglehart states.
The biggest surprise for some readers will be the fact that the biggest change has occurred in the author's own homeland.
Having shown no change in religiosity between 1981 and 2007, secularism has certainly arrived Stateside.
Belief and practice have slumped, as demonstrated by some telling statistics.
In 1982, 52 percent of Americans said God was "very important in their lives." In 2017, 23 percent gave the same answer.
In 1982, 83 percent of Americans described themselves as religious, a figure which had fallen to 55 percent in 2017.
The percentage of Americans who never attend religious services has more than doubled in this time period, and the numbers who say they have "a great deal" of confidence in America's churches has fallen by almost 75 percent.
In answer to the question as to where this process is heading, the author places a strong emphasis on the Nordic countries, which are among the wealthiest and most unbelieving of nations, coming in at the bottom of the table when it comes to belief in God and the afterlife, as well as public confidence in churches.
Widespread prosperity and the emergence of the strong Scandinavian welfare state model made the populations of these countries more economically secure than their counterparts elsewhere, thus reducing the need for the spiritual comfort and material support offered by churches.
Supporting Inglehart's central thesis further, they are also the countries where individual-choice norms became dominant early on, and he notes that in 1990 the Swedish public "was the first to cross the tipping point where support for individual-choice norms outweighed support for pro-fertility norms."
It is important to note that this book is not anti-religious, nor does it argue that the abandonment of religion is a desirable outcome.
He acknowledges the crucial role which religion has played throughout human history in reducing conflict and establishing clear and beneficial moral guidelines, and also that it improved mental health and encouraged people to work together.
These benefits have not gone away as the evidence, he writes, clearly shows that religious people are happier than non-religious people - including those living in wealthy and secular societies. Inglehart states that people will always need a belief system (though he suggests that this system need not be religious in nature).
Some arguments within the 208-page book are weaker and less supported than others, however.
When examining the secularisation debate as it relates to American society, Inglehart points to his earlier work which attributed the relatively high levels of religiosity in the US to "its high levels of inequality and weakly developed welfare system," which brings with it far more insecurity for ordinary Americans.
This, however, does not explain why religious practice is much higher in middle and upper-class American communities, as has been clearly shown since then by Charles Murray's Coming Apart , Tim Carney's Alienated America and other works.
If economic insecurity led to people being more attached to their churches, we would be witnessing a very different reality in America, one where those at the bottom of the socio-economic ladder were most likely to be found in the pews.
Related to this, Inglehart's analysis is too individualistic in general, and does not place a sufficient focus on the social role which religious communities play.
As a result, the decline of religion in advanced Western societies is not examined in the context of increasing atomisation, where societies are wealthier, but where broad swathes of people are less likely to vote, join a union, buy a newspaper or to engage in any other social activity which was far more common in previous generations.
His analysis of the relationship between religion and politics in America also appears simplistic, and too close to the conventional views of an American left-liberal suspicious of traditionalist viewpoints.
Explaining his country's dramatic secularisation, he suggests that "[s]tarting in the 1990s," the Republican Party began to focus more on issues such as same-sex marriage and abortion, and that this has driven younger social liberals away from religion.
But the Republican Party had not changed significantly from that which existed in the overwhelmingly religious society of the early 1980s, and America is still home to a vast array of more theologically and politically liberal Christian churches which could have catered to those put off by the so-called Religious Right.
The most underdeveloped component of Inglehart's book relates to the demographic issue.
Although it is clear that the most secular countries in the world are comfortable, prosperous societies, the fact remains that the wealthiest countries in the West all have fertility rates well below replacement levels, and Nordic nations - and other countries with extensive welfare systems - are no exception to this.
Given that fact, it is clear that the prevalence of "individual-choice norms" is not sustainable in the long-run.
Also, as the political scientist Eric Kaufmann has shown, there are major differences in fertility rates between religious and secular communities, even in strongly liberal countries such as the Netherlands.
Indeed, the author's suggestion of increased immigration as the "most obvious" way of solving the problem of declining fertility would likely be another way of mitigating the secularisation of wealthier societies, given who those immigrants would likely be and where they would likely be coming from.
Religious decline and demographic collapse appear destined to be part of the future of all of the higher income countries, and more and more middle-income countries - such as those in Latin America - are moving in this direction too.
A more secular tomorrow is in store, even though it is already clear that secular societies have no long-term future. Professor Inglehart is right about the decline of religion, and appears to be partially right about the causes of this most consequential change.
But on the question of what is coming next, that is still anyone's guess.