The formal relationship between the Church, be it the Catholic Church or other religious denominations, and the State extends the relationship between faith and politics onto an institutional level. The Catholic Church in particular has a long history of theological and philosophical reasoning as to how the Church and State ought to interact. Although some particular aspects of this relationship have fluctuated over the centuries, certain core principles have endured the test of time. They should also endure through our current secular age.
In the view of the life of faith, the State can only pass laws that concern faith’s moral dimension. Truths revealed by God that have both a supernatural origin and a supernatural end, such as teachings on the divinity of Christ, the real presence of Christ in the Eucharist, or the immaculate conception of the Blessed Virgin Mary, as important as they are, do not have any bearing on the tasks of government. We do not seek civil laws to coerce the spiritual life of individuals, such as requiring prayer, fasting, or attendance at church. Doing so would violate one of the essential elements of faith: that we respond to God freely buy our own wills, not by the command of any other. …
At the same time, however, it is right and beneficial for the State to pass laws that provide a means of fostering religious faith and the moral life, since the exercise of these lies at the heart of human welfare and the common good. While the State cannot command church attendance, it can promote attendance by, for example, requiring stores to be closed on Sunday until a certain hour. The State has long promoted the moral life by limiting or prohibiting certain activities that can lead to vice, to destruction, or to reckless death — limitations on alcohol sales and gambling, and prohibitions of prostitution and drugs are just a few ways in which the State uses its power in the moral sphere for the promotion of the common good. …
The Church cannot and must not take upon herself the political battle to bring about the most just society possible. She cannot and must not replace the State. Yet at the same time she cannot and must not remain on the sidelines in the fight for justice. She has to play her part through rational argument and she has to reawaken the spiritual energy without which justice, which always demands sacrifice, cannot prevail and prosper. A just society must be the achievement of politics, not of the Church. Yet the promotion of justice through efforts to bring about openness of mind and will to the demands of the common good is something which concerns the Church deeply.