Written by: Christopher Bellitto
Religion--whether Christian, monotheistic, or otherwise--found itself challenged or sometimes even shunted aside as modernity developed. While it is untrue to say that the Scientific Revolution and Enlightenment were entirely secular and anti-religious, the cumulative result of their changes in worldview tended to devalue religion as the central glue of society, specifically when it came to using religion to bolster a particular form of government, such as divine-right monarchy.
The case of Galileo points out the limits of religious authority. Copernicus (1473-1543), a Polish astronomer, was pretty sure that the sun and not the earth was the center of what is, in fact, a solar system. Galileo (1564-1642), with more sophisticated tools in hand, proved Copernicus's theory, leading to conflict with Pope Urban VIII. The issue, as we see now from a long view, was not so much the scientific facts, which cannot be denied, but Galileo's assertion that the Church shouldn't be in the science business--a fact that Pope John Paul II recognized in his 1992 rehabilitation of Galileo.
So, too, the Enlightenment idea of liberalism--that is, a large measure of individual human freedom in virtually every sphere of thought and action--hit resistance when it came to religion. While some continued to argue for a close connection between the state and religion (integralism), most Enlightenment thinkers wanted to separate church from state. Indeed, what we find in modernity is a range of "isms" that competed with religion for a person's ultimate allegiance: nationalism, materialism, secularism, industrialism, capitalism, communism, imperialism, socialism, skepticism, and Deism--any of which could attain the status of a new religion. Moreover, the principle of toleration of religious pluralism tended to reduce Christianity's monopoly on western thinking, as Protestantism had cut deeply into Roman Catholicism's monopoly of ancient and medieval Christendom in Europe.
It is often, though mistakenly, said that the Roman Catholic Church went into a siege mentality after the Council of Trent (1545-1563), meeting Protestant challenges with a string of condemnations and then retreating behind her walls. There were fairly forward-thinking ideas in Trent, and the centuries after the council witnessed innovations in religious orders (Jesuits, Ursulines) and missionaries in Africa, Asia, and North and South America.
It is also true, however, that when the French Revolution's secular tendencies, picked up by Napoleon shortly afterward, directly assaulted the Roman Catholic Church--to the degree that Napoleon took two popes prisoner--Rome did indeed withdraw because she saw the world as a dangerous place. This did not last long, however, and many late 19th-century Roman Catholic academics, historians, archeologists, liturgists, and scripture scholars embraced modern ideas and methodologies like textual criticism. This encouraged them to focus on the early Church and uncover what she was like at the beginning.