Troubles with religion
Christianity and Islam structure to the religious beliefs of more than half the world's population, and they are jointly responsible for a wide array of meaningful goods in peoples lives, including comfort, solace, inspiration, (a measure of) relief from anxiety about death, and moral guidance. For all of their popularity and human significance, though, there are very good reasons to doubt that either one of them represents a plausible or healthy spiritual theory of reality.
Below is a short introduction to some of the most powerful, including the moral character of revelation, the inconsistency of revelation, the story of how revelation purportedly came to be in the world, and the way revelation has been structured and composed.
While it can be unpleasant for anyone who believes in the truth of one of these religions to experience criticism of them, it is worth emphasizing that the failure of religion to provide a plausible theory of reality does not by itself show that doing that is impossible. In seeing what is wrong with religion, we put ourselves in a better position to rethink the whole question of life and its meaning from a spiritual perspective.
The moral character of revelation
It stands to reason that if god truly was the author of either the Bible or the Quran, those books should come to us bearing a morally faultless character. Unfortunately, while they both contain many examples of morally excellent ideas—like being honest and just, refraining from evil, and helping the poor and the needy—they also contain some of the worst moral claims imaginable. Below are three examples to illustrate their moral inadequacy.
The Bible on Women: Women were created beneath men (Genesis 3:16, 1 Corinthians 11:3), and must submit themselves in obedience to their husbands (Colossians 3:18, Ephesians 5:22–24). In times of war, it is morally permissible to subject women to rape (Deuteronomy 21:11–14). They are to learn quietness and submission, and are not allowed to teach or hold any authority over males. If they have faith and love and holiness, they will be saved in the end through childbearing (1 Timothy 2:9–15).
The Bible on Disbelief and Hell: Unbelievers are evil (Hebrews 3:12) and suffer from the wrath of god (John 3:36). God sternly warns that the accursed will be cast into the furnaces of hell (Matthew 13:41–42) where they will experience everlasting destruction (2 Thessalonians 1:7–9), be tormented with brimstone (Revelation 14:10–11), and suffer eternally (Matthew 25:41–46; John 5:28–29). As bad as hell is, god has “closed the eyes” and “deadened the hearts” of some so that they will never believe in him (John 12:37–41, 2 Corinthians 4:4).
The Bible on Execution: Among the list of people whose deaths are required, the Bible tells us to execute all homosexuals (Leviticus 20:13), adulterers (Deuteronomy 22:22, Leviticus 20:10), Sabbath breakers (Exodus 35:2), and blasphemers (Leviticus 24:16). It even goes so far as to demand the deaths of any virginal women who are engaged to be married and are raped in a city (Deuteronomy 22:23–25).
Pause a moment to allow the thought of that to wash over your conscience. If you are female, a virgin, engaged, and you are raped, you must die for it. Arguably worse, if the victim isn't engaged when raped, her rapist must purchase her from her father and take her as his wife. The marriage is permanent; she may never divorce him (Deuteronomy 22:28–29).
The Quran on Women: The Quran announces that men have authority over women, for women were created a degree below men (4:34). Women are told to remain faithful and chaste, to keep their gaze lowered, to cover themselves in public, and to avoid stamping their feet (lest the sight of their ankles and legs be revealed; 24:31). A woman’s value as a witness is half that of a man’s (in the case of recording debts at least; 2:282), and they are entitled to inherit only half of what a man is (4:11). Menstruating women should remain socially isolated for the length of their menstruation (2:222), but at all other times may be used for sex by their husbands (2:223). Capturing females as sex slaves in times of war is also perfectly fine (33:50).
The Quran on Disbelief: The Quran says that there is nothing worse in the sight of god than those who do not believe in him (8:55, 6:21). Not only are unbelievers liars (43:20) who should be kept away from places of worship (9:28), in the eyes of god they are quite literally the worst of all people (98:6, 30:45) and are unfit for friendship (5:51, 9:23, 4:89). Even most Jews and Christians (who are given special recognition in the Quran as “people of the book”) live terrible lives (5:59). Though god despises unbelief, he has set a seal upon the hearts of some people so that they will never believe in the truth of Islam (2:6–7, 14:4, 39:23).
The Quran on Hell: Hell is a place of eternal punishment and torture with fire (4:14, 4:168–169, 5:36–37). Those who reject god and “the revelations” will have yokes placed around their necks and will be dragged through boiling liquid while being taunted (40:70–76). They will have their skin consumed by fire, whereupon it will be replaced and then burned off again so that they may “taste the torment” (4:56). The inhabitants of hell will be made to drink boiling water (6:70) and will not be able to drive off the fire from their faces and backs (21:39). They will wear clothing made of fire, their skin and organs will melt, and they will be impaled upon iron hooks (22:19–22).
Now, I don't know about you, but I find myself wholly incapable of believing that god could have had anything to do with statements like these. To place these words in the mouth of god is to only make a terrible parody of the idea of him.
The inconsistency of revelation
It is bad sign for the truth of a religion when its own revelation can't agree about what happened. Consider one of the most important events recorded in the whole of the New Testament as an illustration—the discovery of the empty tomb.
So the story goes, Jesus's body was taken down following his crucifixion and placed in a sealed tomb. Sometime thereafter, a group of women went to his body in order to anoint it with spices. Who went? It depends on which Gospel you ask. It was either Mary Magdalene and another Mary (Matthew 28:1); Mary Magdalene, Mary the mother of James, and Salome (Mark 16:1); an unspecified group of women (Luke 24:1); or Mary Magdalene all by herself (John 20:1).
When whoever it was that went there got to the tomb, which had either been left guarded (Matthew 28:4) or unguarded (the three other Gospels), they found either that the stone covering the entrance had been rolled away already (Mark 16:4, Luke 24:2, John 20:1), or that there was an angel there to roll it away in front of their eyes (Matthew 28:2). In the reports given in Matthew and Mark (Mark 16:5) there was a single angel waiting at the tomb. However, in Luke there was two (Luke 24:4), and in John there was none.
For those Gospels in which there were angels present, the women were either told to go and tell the disciples that Jesus would meet them in Galilee (Mark 16:7), to tell the disciples simply that he has risen (Matthew 28:7), or just to remember that Jesus had told them while they were in Galilee that his death was necessary (Luke 24:6–7). Since there were no angels in the Gospel of John to issue instructions or give reminders, the Gospel has Mary Magdalene go on her own initiative to tell the disciples that the tomb was empty (John 20:2).
Clearly, at least some of the claims made by these Gospels must be false, for they are mutually inconsistent in the details. Yet if revelation can be wrong about at least some things, does that not suggest it can be wrong more deeply? After all, what are the chances god would be happy to have errors this factual egregious in revelation?
The Quran also contains a number of internal contradictions. For example, it tells us that the Egyptian Pharaoh of Exodus fame was both drowned (17:102–103) and not drowned (10:90–92), that drinking alcohol is both permitted (16:67) and not permitted (5:90), that Muhammad was the first Muslim (39:12) and that Moses was the first Muslim (7:143), and that god sends people astray from the message of Islam (17:97) and does not send people astray from the message of Islam (9:115). Again, is this something that god can be easily imagined building into his revelation? Isn't the better explanation for the incoherence of the Bible and the Quran that god had nothing to do with them?
The story of revelation
The story of how revelation came to be in the world is just as bewildering. As many people know, the Gospels of the New Testament were not written by anyone who knew Jesus personally, but by unknown authors who wrote at least a couple of generations after Jesus died. (While the Gospels all have names associated with them—Matthew, Mark, Luke, and John—these are not the names of the authors, but of people who were (at one time) mistakenly thought to be the authors. Since we don’t have anything else to call them by, those names stuck.)
Whoever wrote the Gospels, their original work is not what found its way into the Bible. In fact, so far as we know, the originals no longer exist. What did make it through were copies of the originals that were produced sometime later. Unfortunately, not only do all of the known copies contain copy-errors (mostly harmless, but in some cases significant mistakes), it appears that some scribes took it upon themselves to make additions to what they were copying.
The story found in the Gospel of John (7:53–8:11) of Jesus saving the life of an adulterous woman (by proclaiming to those who would kill her that those without sin should cast the first stone) is one such example. Lovely as it is, this story doesn't exist in the earliest known copies of the Gospel. At some point somewhere along the way, someone just added it in.
That outside changes could have made their way into the Bible is certainly a problem for the idea that the Bible is the work of god. Even more of a problem is the fact that there are whole letters included in the New Testament that are known to be forgeries. For reasons ranging from considerations of style and content to forensic analysis of the language used, considerable scholarly agreement exists that Colossians, Ephesians, 1 and 2 Timothy, Titus, and 2 Thessalonians were not written by the Apostle Paul, despite all alleging to have been.
What we have to imagine, then, is that Jesus would come to Earth to educate the world about god and save humanity from its sins, yet would not write a single word down about any of this himself. The writing task would be left to others to complete. And that they would, but only anonymously, only generations after he died, and only on the basis of what they had heard from others about him. Then, copies of what they had written would be made and the originals lost to history. Once that was done, the New Testament would be compiled from the surviving copies, but in doing so it would come to include both copy-errors and stories the scribes decided to invent for Jesus along the way. Finally, the New Testament would be permitted to include whole letters that were mistakenly thought to be authentic but were in fact forged in another's name.
It is hard to see anything divinely-minded about this plan for revelation. While small changes to revelation would be enough to raise serious doubt, that whole forged letters could have ended up being included in what we're told is god’s timeless message speaks compellingly against the idea that it is any such thing.
As for the Quran, it too has an unlikely history. The Quran is believed by the majority of Muslims to be a word-for-word, perfect, and unchangeable record of what god revealed to Muhammad in the 7th century over the course of 23 years. Like Jesus, Muhammad made no effort to carefully write down god’s revealed message. Allegedly he could not, even if he had wanted to, for he is said to have been illiterate. Islamic tradition therefore holds that this task was taken up by others by either memorizing or recording down the divine transmissions on scraps of paper, leather, and other materials. It was only after Muhammad died that the Quran was brought together as a single book, and—we're to believe—in precisely the way that god had always intended for it, down to the last word and letter.
The structure of revelation
Then there is the matter of how revelation was put together. Consider the Bible’s New Testament, which consists of a series of reports and letters detailing both the life of Jesus and important religious information.
Now, as anyone who has ever actually read the Bible will have discovered firsthand, just stringing together a whole bunch of different accounts and letters from different authors addressed to different people, about varying topics and themes, and without any scene-setting or introduction, doesn't necessarily result in the most systematic, coherent, and clear picture of what god actually wants from us. It can produce the very opposite, in fact.
The Quran runs into the same problem. It comes to us in chapters (called suras), yet confusingly, the chapters are not arranged in a meaningful order, like by topic or chronologically from earliest to latest, but (with the exception of the very first sura) from longest to shortest.
Think about that. Why god would have chosen to arrange revelation like this? Its only effect is to make reading the Quran feel a lot like you've just walked in on a conversation halfway done between two people you don’t know, neither of whom bothers to stop and run you up to speed, and which flips randomly between different topics.
The 111th sura provides a good illustration of just how bewildering reading the Quran can be. The sura is one of the shortest, and appears without any context towards its end. Here is what it says:
111:1 The power of Abu Lahab will perish, and he will perish.
111:2 His wealth and gains will not exempt him.
111:3 He will be plunged in flaming Fire,
111:4 And his wife, the wood-carrier,
111:5 Will have upon her neck a halter of palm-fibre.
So what do we learn? That some guy we don’t know and his wife were condemned to hell for doing something we’re never told about. That’s it. End sura.
Putting aside the severity of hell as a punishment, the point here isn't what the Quran says but how it says it. Would any being wanting to be understood and convey important truths construct a timeless text to all of humanity that looked like this? The question is rhetorical, for the answer is clear: no.