The Sermon on the Mount may be the most radically egalitarian document around. Throwing the money changers out of the temple also put the rich in their place. Ditto for the camel passing through the eye of the needle. Yet, Christianity fosters inequality in practice. It reconciles the poor to their misery: it is their opium.
Pie in the sky
That is what Karl Marx argued in explaining why Christianity and other religions work against Sermon-on-the Mount-type socialism. The problem is that religious people focus on an afterlife (or an altered state of consciousness) where the problems of inequality, injustice, and exploitation magically vaporize.
This otherworldly perspective is often called "pie in the sky" because it does nothing to put pie on the table for hungry people but fobs them off with unverifiable promises to be delivered after death.
Not all religious people are willing to turn their backs on the Sermon on the Mount, of course. This approach to change as a present-world phenomenon is reflected in the liberation theology of Latin America where Catholic priests threw in their lot with the revolt of socialist revolutionaries against corrupt, mostly U.S.-backed dictators. Embraced by left-wing intellectuals, these radical priests were, predictably, treated like heretics by the Vatican.
"Flat" societies less religious
Such church rejection of leveling movements is nothing new, of course. There are good reasons why organized religions generally side with powerful elites and autocratic rulers:
They derive power and influence by siding with rulers whereas political leaders derive legitimacy by cozying up to religious leaders. It is a win-win alliance whereas churches that oppose monarchs or dictators tend to lose out.
More equal societies are less religious as illustrated by the difference between Europe and the U.S. -- Europe being both more equal and less religious.
Comparatively unequal societies experience a lack of social trust and a great deal of fear, uncertainty, and human misery that boosts religion.
Why does misery strengthen religion? In my book Why Atheism Will Replace Religion: The Triumph of Earthly Pleasures Over Pie In the Sky, I argue that when living conditions are bad, people turn to religion for an emotional answer to problems such as political oppression that are difficult to solve in concrete terms. I present overwhelming evidence that all manner of misery from disease and natural disasters to income inequality is correlated with religiosity and belief in God.
The history of inequality is complex. Hunter-gatherer societies were essentially flat.One person is every bit as good as another. They were not very religious.
Agriculture and the advent of storable food surplus created social inequality as illustrated by the Biblical story of the Pharaohs enslaving the Jews by lending them food. Social inequality increases again in industrializing countries where tycoons accumulate huge amounts of capital and use it to control government and oppress workers as illustrated by Robber Barons in the mould of Dale Carnegie.
Such excesses are rolled back by modern democracies where leaders are selected by ordinary citizens who can no longer be exploited by aristocrats, or oligarchs -- at least in theory. Such political empowerment boosts income equality by various means from minimum wage statutes and collective bargaining, to public education and progressive taxation.
Along with the rights and freedoms of modern democracies, citizens experience a quality of life that is unequaled in history with improved health and increased social trust. This brings an unprecedented decline in religion.
These phenomena may be illustrated by Scandinavian countries that provide cradle-to-grave support of the critical needs of their citizens. Instead of the deference shown to religion in most places around the globe, religious people, and institutions, elicit an air of casual condescension there (4).
The Sermon on the Mount is put into practice via leveling government policies. Doing so destroys religion.