At first glance, this seems incorrect. After all, it could be argued the general population of the West was at its most spiritual and religious when living standards for the average person were quite low, and that rising standards of living demonstrate an inverse relationship to religion. In short, increases in material comfort and wealth led to decreases in spirituality and religion. To me, it seems the opposite should have occurred, if not immediately, then perhaps sometime shortly after the Industrial Revolution. The extra wealth, time, and freedoms rising standards of living provided the average person should have been invested into spiritual and religious growth. Instead, the increases in material wealth and comfort were invested into the acquisition and enjoyment of more material wealth and comfort at the expense of spiritual and religious growth.
Of course, what I have stated above is a sweeping generalization of the grossest kind, and Western history is filled with various religious movements that attempted to buck this trend through various forms of asceticism, but I think these religious impulses toward severe material abstinence amounted to little more than regressive reactions against the weakening of religion in the face of the strengthening of the material in the minds of men. In my mind, rising standards of living themselves were not the cause of the wrong turn; the wrong turn occurred when people became seemingly incapable of framing rising standards of living within the required context of religion.
The inverse relationship between religion and material comfort and wealth is often presented within an either/or paradigm, a paradigm that is apparently supported by the Synoptic Gospels, especially the passages dealing with serving two masters and rich men getting into heaven. Heaven was an easy sell when life for the average Westerner was poor, brutish, and short. Denied means or access to material comfort and wealth during mortal life, heaven became a sort of panacea and reward for the afterlife. The rich, on the other hand, could enjoy a sort of heaven on earth, but this enjoyment put their chances of getting to heaven at risk.
This sort of either/or framing never made much sense to me. As far as I'm concerned, the dichotomy of a high standard of living and religion is a false. The either/or division it has created should have been short-lived, and it should have given birth to the harmony of 'and'. Generally affluent, pleasant, civilized, and long mortal lives should have manifested generally deeper, more intense, more meaningful, and purposeful religious lives, but this required a radical shift in human consciousness, a radical shift that did not occur and has still not occurred. This radical shift should have entailed some sort of recognition that increases in material comfort and wealth, though good, provide human life no real meaning or purpose, as well as the understanding that these increases in material comfort and wealth are positively poisonous to the soul once the framework of religion is discarded.