This Google Ngram search shows that the word economics (a representative term from the economy function system) emerged in about 1880 and started a rapid rise in about 1905. It declined from 1940 to about 1945–the World War II years–then regained it momentum through the 1990s.
Here is an Ngram for a representative word from religion–salvation–compared to economics.
Salvation peaked in about 1830, which was the time of the Second Great Awakening in the United States. Then it fluctuated for about a decade before starting a steady decline. From 1880 to about 1940, the fortunes of the words salvation and economics were near mirror images, with one going down and the other up. This pattern suggests that English speakers began to put their faith in economists rather than preachers or theologians. Economists were better equipped to describe the emerging complexity of modern, functionally differentiated society. Similar results were found for German and French translations of salvation. Western society had just become too complex to be persuasively reduced to a religious code.
Below we see that the terms economic and economics both emerged in about 1880, but economic (adjective) rises much more rapidly than economics (noun). This is presumably due to the fact that adjectives can be attached to many nouns–economic indicators, economic forecasts, etc.
Here is an interesting comparison of business and salvation in American English between 1800-1900.
In about 1812, salvation starts to decline, while business starts to rise in 1817. (However, salvation did rebound during the Second Great Awakening.) If we extend this to the year 2000, we get this:
In this view, we see that business peaked in 1923, which were economic boom years. Then it declines steadily before regaining its footing in 1976, the year Jimmy Carter was elected. This suggests that writers had turned their attention to business or economic issues before the Reagan presidency. As for salvation, it flat-lined starting in the 1930s.
Here is a comparison of two adjectives, economic and moral (a term commonly used in religious contexts), from 1800-2000. I limited moral to adjectives to eliminate usages such as “the moral of the story.” The two lines cross in 1922, at the start of the “Roaring 20s.”