The Church and Civil Power
The issue of the Church's intervention in the political sphere often arises, invoking the old liberal principle of the separation (autonomy) of religious power from political power, "a free Church in a free State," as it was said during the time of our Risorgimento. Consequently, it follows that, just as the State should not deal with religious matters (doctrine and liturgy), the Church should not involve itself in political matters, namely the laws enacted by the State.
In reality, the issue is far more complex: let us try to examine it. The Church, while no longer having any direct power of intervention in State institutions, still maintains a strong political influence in the sense that its positions can greatly impact the attitudes of citizens (voters).
Let’s clarify the issue a bit. In the past, even what we call an absolute State operated within the general principles of society, which often coincided with religious ones. There could be a certain degree of tolerance for minority religious groups (for example, Jews or Muslims), but society still identified itself with a dominant faith. If societal principles aligned with religious ones, then the Church was recognized as the sole interpreter of those principles, and it logically followed that it could censor or even depose sovereigns who strayed too far from them. In the Middle Ages, excommunication of a sovereign implied the nullification of the subjects’ oath of loyalty—in practice, a deposition, as occurred with various rulers.
The Church, therefore, had a function similar to that of our constitutional courts, even if these can only annul laws and not depose governments. At that time, there was no separation of powers; those who made the laws also enforced them. A similar system can be observed in the current Islamic Republic of Iran, where the Supreme Leader has a role comparable to that of our constitutional courts, albeit with extensive authority that allows him to direct the State far more than the elected government. In our own history, the Church has often extended its intervention, using religious principles as a pretext to wield direct power. On the other hand, even our constitutional courts sometimes "overreach" their role, creatively interpreting constitutional principles.
In short, the principle is accepted, but there has always been, and still is, a conflict over its application. With the formation of the liberal State in the 19th century, the Church's function of oversight diminished. With religious freedom, the first and mother of all freedoms, fundamental principles were no longer religious but those enshrined in constitutional charters, which effectively define democratic and secular principles. Therefore, the Church should only concern itself with religious matters, not political ones.
But what are religious matters? One part concerns doctrine (dogmas, creation, the divinity of Christ, the Assumption of the Virgin, and so on) and another part concerns liturgy (obligations and organization of religious practices: sacraments, Mass, prayers). However, every religion also has ethical principles. The fact that the Church proposes a religious principle (e.g., opposition to war, aid to the needy) does not mean that it concerns only believers: such principles are considered by the Church, as by any religion, valid for all. In short, the nature of Christ or celebrating Mass in Italian or Latin concerns only believers, but peace among peoples or social justice concerns everyone, and when the Church upholds certain ethical principles, it addresses both believers and non-believers (referred to as natural ethics).
In the modern world, the Church cannot intervene in State structures; it cannot, for example, remove officials or enact or repeal laws, as it has no means to do so. However, it can freely express its teachings, thus influencing a certain number of citizens who will vote and support particular principles. Therefore, on the one hand, the Church cannot intervene institutionally in the State, but on the other hand, it can have a strong influence on citizens, who in turn determine the formation of governments, parliaments, municipalities, and regions.
The Church can propose, but it is ultimately up to the citizens to decide, just as feminist associations, LGBTQ groups, environmental movements, and animal welfare organizations do, and so on. Thus, without any legal power to intervene in State matters, the Church can still have a great influence on it.
One significant example was the choice between communism and democracy in the last century, when the Church contributed greatly to the affirmation of the Christian Democratic Party and the limitation of the spread of communism, aiding in the "economic miracle."
If today there is a law prohibiting surrogacy (or "womb for rent"), it is not because the Church enacted that law, but because the majority of citizens elected a government and a parliament that enacted it, believing it would garner greater favor among voters: this is democracy. In other cases, however, the Church has been defeated: despite its opposition to divorce and abortion, the majority of citizens approved those laws, and the Church certainly cannot repeal them.
However, this does not mean it cannot continue to fight them by democratic means. Obviously, the fact that a majority decides something is good does not mean it actually is: there will always be a certain number of citizens, more or less large, who believe that it is wrong, and who have every right to express themselves. Expressing oneself (not violating) against existing laws is a hallmark of democracy. It may happen that one day the conviction that abortion is wrong (an act of murder) becomes widely shared by the majority: this is the normal course of democracy.
In this context, the Church proposes what it believes is right according to its doctrine: it is then up to the citizens to decide. This is democracy.