Though many say ninja monk flick Book of Eli is about Christianity, it's actually about rebooting the old church for a new world. Like many SF stories about the emergence of a new faith, Eli questions religion while defending it.
In the pantheon of science fiction tales, Book of Eli is just one of many that imagines future, mutated versions of contemporary religion. Like Margaret Atwood's recent novel The Year of the Flood or the classic Dune, Book of Eli makes just a few telling tweaks in familiar forms of faith. These stories suggest something that many would consider blasphemous: Religion is a product of history, and it changes with the times.
The Democracy Of Heaven
Book of Eli is, as its title suggests, a movie that tells the story of a new chapter in the Christian Bible. But it's also a reboot of the New Testament, retelling the origin story of Christianity. Our knife-wielding badass Eli, who risks everything to walk across the country and deliver his Bible to the only printing press in all the land, could be viewed as a Christ figure of the future. He spreads the word of old-school Christianity, but he's remaking the religion as he goes, incorporating printing presses, Johnny Cash, and ninja skills into traditional lore.
But the tweak here goes beyond suggesting that Johnny Cash could become part of tomorrow's hymnals. Book of Eli transforms the origin story of European and American Christianity, converting the chalk-white faces of Jesus and his apostles into the battle-scarred face of a powerful black man. The figure of Eli is a far cry from the classic imagery of the manger that many Americans grew up with. And in the end, Eli leaves behind a powerful female apostle to spread his word. With those changes - a holy book now starring a black man, who chooses a white woman as his apprentice - contemporary Christianity gets a makeover.
Atwood's Year of the Flood takes a similar tack, transforming the prophets of Christianity into environmentalists and biologists - and creating a hymnal devoted to ecology. While the basic tenets of Christianity remain the same, and the methods of worship are recognizable, Atwood suggests that Christianity can only survive into a post-apocalyptic world if it places the preservation of nature at the heart of its faith.
Likewise, in the Dune series, we learn that the humans who colonize space have a holy book called the Orange Catholic Bible (OC Bible), an amalgam of many Earth religions, including Christianity and "Buddhislamic" tradition. This new version of the Bible also incorporates ideas about artificial intelligence and computing machines. Indeed, it was written in part to justify the "Butlerian Jihad" that purged society of "thinking machines" because OC Bible worshipers believe that AI destroys the beauty of the human soul. Though these Jihadists use the language of Judeo-Christianity, their central tenant is that nobody should make a machine that emulates the human mind.
Is the Christianity of today the same as that of the OC Bible? Is it even the same thing as Eli's Christianity? The answer is more or less no. These are fundamentally different religions that partake of the same tradition but transform it entirely. Religion is a function of social change over time.
But looked at from another angle, these stories about the future of religion suggest the opposite to be true. Christianity and other forms of faith endure, even when humanity is no longer recognizable. Even as we conquer space and build perfect AI, religious faith guides us.
Oddly, a series of books that has outraged Christians seems to be the best argument in favor of this idea. In Philip Pullman's His Dark Materials series, we see a plot arc that shares a lot with Book of Eli. In this series, a society on a parallel Earth is being threatened by a cruel, dictatorial version of the Catholic Church called the Magisterium. The people who run the Magisterium want to deprive people of pleasure (especially sexual pleasure) to gain more social control. Meanwhile, a group of renegades fight to unseat both the Magisterium and the corrupt order of angels who rule everything. As the series comes to an end, faith is not destroyed. Instead, a new set of prophets arise and a new ruling order is established in Heaven. There is, as Pullman writes, "the democracy of Heaven," and the new prophets are a pair of young lovers whose romantic and sexual union forms the basis of a new kind of faith.
Compare this idea with Eli being the new prophet, or ecology being a new form of godliness. Christianity isn't being trashed - it's just manifesting itself within new people and new ideas.
Jacqueline Carey makes a similar point in her Kushiel series, where Europe adheres to a faith that's an outgrowth of Christianity - her characters, living in an alternate Middle Ages, worship Christ's son with Mary Magdalene, a holy man named Elua. Like Pullman's "democratic" Christianity, Elua-worship involves an exaltation of sexuality as a form of holy love.
God Is Change
Sometimes science fiction goes far beyond tweaking existing religions and invents seemingly new ones from scratch. Such is the case in Octavia Butler's post-apocalyptic novels Parable of the Sower and Parable of the Talents. In those novels, Butler imagines a somewhat Eli-like figure in Lauren, a black woman who must wander the apocalyptic roads of California after the US government breaks down. She tangles with groups of repressive, militant Christians (like bad guy Carnegie and his henchmen in Book of Eli), and ultimately founds a community based on a religion she invents herself. That religion's central premise is "God is change," and Lauren uses that idea to push humans toward colonizing space.
Butler was fascinated with the idea of a faith that could motivate people to engage with scientific progress. Lauren's religion is an alloy of Christianity and astrophysics, which takes as its basic premise something that happens to other religions organically over time: They change.
On a slightly goofier note, Bill and Ted's Excellent Adventure makes a similar move with its futuristic religion. When Bill and Ted travel to the future, we see that the awesome, peaceful, and scientifically advanced society there is founded on the worship of, well, them. The tenet of the new religion? "Be excellent to each other."
The premise of all the stories I've talked about so far is that religion evolves. Either present-day religions mutate to suit new societies, or future societies create new religions that suit their needs. But some SF tales take a more cynical view, imagining that religion will never change - and therefore society will never progress. Indeed, it might regress.
All Of It Will Happen Again
That's certainly the idea in dark post-apocalyptic novel A Canticle for Leibowitz, where a bizarro version of the Catholic Church is busily trying to protect holy documents discovered in a fallout shelter. The Earth has been torched in a nuclear war, and as the book unfolds we watch society rebuilding itself from the neo-Dark Ages to a futuristic world - always with an unchanging religion at its heart. Just as religion doesn't change, neither does humanity, which is heading straight for nuclear wipeout again. Though critics have argued persuasively that this novel is about how religion serves as a raft in the storm of historical transformation, it's easy to see the other side too: As long as God does not change, neither will humanity embrace the changes required to stop self-annihilating.