Religion is usually considered one of the function systems of society; it is one of ten described by Steffen Roth and Anton Schütz (2015) in “Ten Systems: Toward a Canon of Function Systems,” and Luhmann wrote a book (though he didn’t finish it himself) on the religion system. But as Roth, et al. (2017) show in show in “Futures of a distributed memory: A global brain wave measurement (1800-2000),” the religion system has declined in influence over the last two centuries.
The major global religions, including Roman Catholicism and the various moderate Protestant denominations, moderate Islam, Judaism, Buddhism, and Hinduism, are carriers of tradition. They preserve cultural memories, in this way offering stability and a sense cultural identity. They also provide a sense of temporal stability by removing the uncertainty about, for example, what a Christian family is going to do every Sunday morning. Or for a Muslim who prays five times a day, fasts during Ramadan, etc., the uncertainty of what he or she is going to do five times a day and during Ramadan is removed. The same goes for an observant Jew on the Sabbath, during Hanukkah, and so on. Rituals, in general, reduce uncertainty by telling us what we should do in times of stress or transition, such as when a family member dies and we know we must have the body taken away and then prepare for some kind of funeral or memorial. Ritual tells us what’s next, or what we’re expected to do next. On a more superficial level, religion can provide a network of friends and social support, but the same end might be achieved by a book club or bowling league.
Religion, however, is unique–and not just another social organization like a book club–in that it posits a transcendent God or some kind of transcendent design outside of the world we can directly know or perceive. This is a necessary, noncontingent reality; it is a kind of unmoving fulcrum on which the world balances. According to Luhmann, religion draws a distinction between immanence and transcendence. In some theologies, God is both immanent and transcendent. In others, He is only transcendent. According to one source,
immanence, in philosophy and theology, a term applied, in contradistinction to “transcendence,” to the fact or condition of being entirely within something (from Latin immanere, “to dwell in, remain”). Its most important use is for the theological conception of God as existing in and throughout the created world, as opposed, for example, to deism, which conceives him as separate from and above the universe. This concept has been expressed in a great variety of forms, including theism and pantheism.https://www.britannica.com/topic/immanence-divine-attribute
Fundamentalist religions offer the same benefits of mainstream religions, but they also seem to be protest movements, which is a separate type of social system (alongside interaction systems, organizations, function systems, and society itself). They directly oppose modern secular society, placing themselves outside of that society. These days, the religions that appear most prominently in the mass media (and, according to Luhmann, whatever contemporary society knows about itself comes from the mass media) are conservative protest movements, often fundamentalist movements. The mass media doesn’t pay much attention to moderate religions because they’re not usually newsworthy–they’re boring. An exception is the news coverage of scandals, such as Catholic priests’ abuse of children. Scandals in any area of society receive mass media attention.
If religion draws the distinction between immanence and transcendence, we have to ask what social problem this distinction is meant to address. There must be a particular social structure that gives rise to the semantics based on the immanence/transcendence distinction. And if this social structure decays or fades away, the distinction would also fade away–meaning that religious communication is no longer meaningful. Semantic change always accompanies structural change. In tribal groups, the social structure included a special person or group or people that possessed secret, sacred, or supernatural knowledge, like a shaman or priestly caste. This person is the intermediary between the gods and ordinary members of the community. This person has one might be called magical abilities. If this class of persons no longer exists—or the concept of secret knowledge loses currenct—then religion dies off. But this is just one possible theory. Luhmann also observed that the need for an intermediary reflects a society with a king who is not directly accessible to ordinary people.
All social systems attempt to resolve a paradox. For religion, the paradox is that immanence needs transcendence and transcendence needs immanence; thus immanence must precede transcendence and transcendence must precede immanence. Which came first, the chicken or the egg? Each assumes the prior existence of the other. This is a logical dead-end, which is why philosophy treats paradoxes as logical errors and religion often appeals to an authority to answer the question.
The way the religious paradox is resolved is by using time. We privilege transcendence and say that it came first. First we have a transcendent God or creator, and this God creates the world. God has always existed, but his creation is not eternal. If we try to imagine the two sides of the distinctions arising together, outside of time, we get stuck. So, in order to see just one, we must block the other–as if we are putting a hand over one eye. But, as Luhmann observes, resolving a paradox in this way simply un-asks the question of how each one can precede the other.