Pope Francis acts out the humility preached by Christian ascetics for two millennia. Yet, he owns what is probably the most valuable art collection in the world. He is not about to sell all he has and give to the poor. Why not?
The central reason is that organized religions emerged as a support system for political hierarchies and continue in that role to this day. If they had turned against the privileged secular authorities, they could expect trouble. There are interesting wrinkles in this story, however, such as the conversion of the Roman emperor Constantine to a dissident religion (early Christianity) and the use and abuse of Europe's Jews by its monarchs.
The Divine Right of Despots
Religious beliefs often provide a justification for the arbitrary assumption, and use, of power by secular authorities, from the divine right of English kings to the deification of Aztec emperors as the guarantors of good harvests.
Ironically, some religious doctrines, specifically Christian teachings, are opposed to inequality. For example, the Sermon on the Mount cheers on the downfall of the wealthy and powerful. The Christian religious authorities nevertheless cozy up to the rich and powerful and side with the elite in preserving social inequality. Religious hierarchies support inequality because doing so serves their own interest as protected members of the elite.
This paradox was appreciated by Karl Marx who recognized that religious authorities stood in the way of the revolutionary changes through which he sought to put the workers in charge of their own government.
The Opium of the People
Marx knew that religion helped the populace to remain calm despite the manifest inequality of the hereditary class system that he wished to overthrow. Religion provided a justification for inequality. It sapped the revolutionary fervor of the masses, rendering them passive in the face of injustice. It was the opium of the people.
Marx recognized that religion justified the hereditary class system. Just as monarchs drew legitimacy directly from God, the class system was bolstered by established religions. Religious adherents were encouraged to obey all their lawful superiors that included not just the monarch and government but also the aristocracy who enjoyed hereditary wealth and political power.
Under the English feudal system, for example, the local squire inherited the right (and duty) to administer justice. This fact is expressed in the satirical couplet:
God bless the squire and all his relations / And keep us in our proper stations.
Whatever religious dogmas might say, organized religions must endorse the ruling authorities if they want to remain in business.
The Rise of Inequality with Agriculture
As societies became more unequal following the Agricultural Revolution, religions grew more intense, and deities were perceived as more powerful and moral (1). The all-knowing deity sees everything an individual does and weighs each of their actions in the scale of morality, ultimately threatening them with everlasting torture in hell (according to the Judeo-Christian tradition). In addition to being the opium of the people, religion served as a virtual police force holding the masses accountable for rebellious thoughts and deeds. Such monotheistic high moral gods were a product of the Agricultural Revolution. Earlier polytheistic gods were weaker and had less control over individuals (1).
Modern Religions and Inequality
Organized religions bolster hierarchical political systems but they are also hierarchical in themselves.
There are two plausible reasons for this. The first is that they are influenced by inequalities in the broader society. The other is that as large bureaucratic structures, organized religions are moat easily managed through a hierarchical organization, as was true of commercial corporations prior to the digital age.
In an increasingly affluent, and increasingly secular, world, organized religion is in a steep decline and churches are unwilling to cede either their wealth, or their status system both of which buttress their authority.
Some religions are less hierarchical than others and the Quaker religion is flatter than Catholicism, for example. It is also worth noting that liberation theology in Latin America opposed class inequalities and supported Marxist revolutions (for which it came in conflict with the Vatican).
Such leveling tendencies tie in to the early Christian church that was also perceived as cult like and extreme.
At least that was the case until it was taken up by Constantine and the Roman Empire. Since then, it has prospered by flattering the powerful and soothing the weak.
1 Slingerland, E., Henrich, J., and Norenzayan, A. (2013). The evolution of prosocial religions. In Peter J. Richerson, and Christiansen,H. Morten, Eds., Cultural evolution: Society, technology, language, and religion (pp. 335-348). Cambridge, MA: The MIT Press.