This is a sort of continuation of the post on negative and positive integration. In discussing the religion system, Luhmann writes,
[What] is so remarkable is that there are so few interdependencies with the inclusion/exclusion regulations of other function systems. Being excluded from religion does not, as in the Middle Ages, exclude one from society. On the other hand, religion can blithely ignore any near exclusion from other function systems, such as not having money, an education, an identity card or chance of being taken seriously by the police of a judge. . . .
[In other words,] religion is independent of inclusions/exclusions originating in other function systems. (Luhmann. A Systems Theory of Religion, 220)
In the European Middle Ages, when society was organized by stratification as well as centralization, religion was tightly integrated with all aspects of society. If the society was defined as Christian, then being a Jew would exclude you from some of the benefits and protections of society. Consider Shylock in The Merchant of Venice. In the United States, even until the mid-20th century, Jews were routinely excluded from elite universities and professions. And today, it is very unlikely that an avowed atheist could be elected President of the United States, but I don’t believe this is any longer true for a European head of state. If functional differentiation progresses, religious identification will not impact success in politics. Even today, Trump is in no way a Christian; however, he still has to pay lip service to Christianity to win support. But in the future, even that lip service will likely longer be necessarily.
The claim that “religion can blithely ignore any near exclusion from other function systems” means, in one sense, that the religion system can accept all of the social outcasts–everyone who is excluded or not seen (invisibilized). In the case of Christianity, this would mean following the example of Jesus Christ, who welcomed all the sinners. Even the most hardened criminal, in this view, is entitled to God’s grace.
This attitude of favoring the poor and the social outcast works well when society is primarily stratified and/or centralized because religion (in opposition to politics) can favor those at the bottom of the social hierarchy and those on the margins of society. That is to say, religion can go against the codes of stratification and centralization and grant more value to the person at the bottom and on the margins. For instance, in the Middle Ages, the “mad” were often considered saintly or holy (See Foucault‘s Madness and Civilization). These outsiders had a protected status.
But under functional differentiation things change. The “insane” are not considered holy. Rather than seeing insanity as a sign of holiness, modern society prescribes normalizing therapy. And being rich does not disqualify a person from heaven; the chances of a rich man receiving grace are no longer like a camel passing through the eye of a needle. Riches, as in Calvinism, could even be a sign of God’s favor. As John Calvin wrote,
Riches in themselves and by their nature are not at all to be condemned; and it is even a great blasphemy against God to disapprove of riches, implying that a man who possesses them is thereby wholly corrupted. For where do riches come from, if not from God?
For Calvin, “Adversity if a sign of God’s absence, prosperity of his presence.” This is pretty radical, as Calvin was rejecting the theology of St. Augustine, St. Jerome, St. Francis, and others. But this theology has certainly resonated in contemporary America, as in the Prosperity Theology. (See The Moral Consequences of Economic Growth, by Benjamin Friedman).
But if we want to be consistent, we would say that being poor, like being rich, is neither a sign of the absence of grace nor of its presence; people do not become poor as a result of moral weakness, lack of religion, or lack of grace. Being rich or poor has nothing at all to do with being moral or with receiving God’s grace. This view would be consistent with antinomianism, which essentially severs religion from morality. If religion is to be a truly autopoietic system (and survive), it cannot be bound to the inclusion/exclusion codes of economy, politics, education, or any other system.