As a philosopher of religion, the way I approach this topic is in terms of a philosophical question: What theory of revelation fits best with the Christian view of God? Put another way, if there is a God that fits the broadly Christian description, how would we expect such a God to reveal the divine nature and will to the world?
Many conservative Christians take it for granted that God has revealed the divine nature and will in and through a specific book. More precisely (although they aren't usually this precise), they believe that God inspired certain human authors at various times in history to write texts that inerrantly express divine truths--and then inspired other human beings to correctly recognize these texts and include all and only them in the comprehensive collection of Scriptures we call the Bible.
Let's call this the theory of biblical inerrancy.
Does this theory fit well with broader Christian beliefs? Is this a good Christian theory about divine revelation, culminating in a good Christian theory about what the Bible is and what sort of authority we should attach to it? I think there are a number of reasons to be skeptical.
Put more narrowly, I think there are a number of reasons why Christians should be skeptical, given their Christian starting points. Let's consider at least some of these reasons.
1. Christianity holds that Jesus is the ultimate revelation of God
Traditional Christian teaching holds that Jesus is the Word made Flesh, the incarnation of God in history. And this means that for Christians, the primary and monumental revelation of God is in the person of Jesus, not in any book (however inspired). It is this fact which motivated George MacDonald to say of the Bible,
It nowhere lays claim to be regarded as the Word, the Way, the Truth. The Bible leads us to Jesus, the inexhaustible, the ever unfolding Revelation of God. It is Christ "in whom are hid all the treasures of wisdom and knowledge," not the Bible, save as leading to him.Biblical inerrantists might argue that nothing precludes God from both revealing the divine nature primarily in Jesus and authoring an inerrant book as a secondary revelation. This is true as far as it goes. But there are reasons for concern.
First, there's a difference between the kind of revelation that Jesus represents, and the kind that a book represents. A person and a book are different things, and we learn from them in different ways. Consider the difference between having a mentor in the project of becoming a better person, and reading self-help books.
Doesn't Christianity teach that God's preferred way of disclosing the divine nature and will is through personal, living relationship rather than fixed words? The problem with throwing in an inerrant book as a "supplemental" revelation is that it can lead to Bible-worship. Given human psychology, there is something alluring about having a book with all the answers. But if God primarily wants us to find the answers through personal engagement with the living God, as discovered in Jesus, isn't there a real danger that fixation on the Bible will distract the faithful from God's primary mode of self-disclosure?
None of this is to say that human stories--witness accounts of divine revelation in history--aren't important. They can motivate a desire to seek out the one whom the stories are about, and they can offer tools for discerning whether you've found the one you seek or an imposter. But once they are seen as secondary, as valuable as a means to an end, the need for inerrancy dissipates. If what really matters is my friendship with Joe, and if I sought out and formed a friendship with him because lots of people told me stories about him that revealed him as an awesome guy I wanted to meet, do I really need to insist that those storytellers were inerrant? Why?
2. The Jesus of Scripture was not an inerrantist
In John 8:1-11, we have the story of the teachers of the law coming to Jesus with an adulteress, and asking Him whether they ought to stone her to death as the Scriptures prescribe. The passage itself declares that this was a trap: If Jesus came out and directly told them not to stone her, He would be defying a direct scriptural injunction.
He avoided the trap: He didn't directly telling them to act contrary to Scripture. Instead, He told them that the one without sin should cast the first stone.
It is a stunning and powerful story (no wonder someone decided to write it into the Gospel of John, even though it didn't appear in the earliest versions). But notice that Jesus didn't tell them to do what Scripture prescribed. Instead, He found a powerful way to drive home exactly what was wrong with following that scriptural injunction--in a way that avoided their trap.
In short, Jesus disagreed with some of the teachings in the Scriptures of His day. In the Sermon on the Mount, he offered gentle correctives to earlier teachings--teachings which started in a direction but didn't go far enough. The lex talionis command to punish evildoers eye for eye and tooth for tooth may, at the time, have served as a restraint on retributive impulses: don't punish beyond the severity of the crime. But for Jesus, that level of restrain was insufficient. It was a start on a path, perhaps, but only that. Jesus followed the trajectory of that path to its conclusion, and enjoined His listeners to turn the other cheek.
In short, it's clear Jesus didn't have the inerrantist view towards the Scriptures of His day that conservative Christians have towards the Christian Scriptures of today. Conservatives might argue that Jesus would view the modern Bible--or maybe just the New Testament?--in the way they favor, even if the approach to Scripture that He actually modeled is at odds with their approach.
Allow me to treat such a speculative claim with suspicion. If Jesus is the primary revelation of God in history, then it strikes me as appropriate to follow His model for approaching Scripture, and respectfully look beyond the letters on the page to the deeper intentions that finite human authors might have missed, noticing trajectories and exploring where they might lead.
3. In the New Testament, Paul distinguished between his views and the Lord's
In 1 Corinthians 7:10-12, Paul says the following:
To the married I give this command (not I, but the Lord): A wife must not separate from her husband. But if she does, she must remain unmarried or else be reconciled to her husband. And a husband must not divorce his wife. To the rest I say this (I, not the Lord): If any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her...I've talked about this passage before, so I won't go into details. What interests me is the distinction Paul makes between his own views and those of the Lord. In this passage, it's clear that Paul did not see Himself as taking dictation from God. He made a clear distinction between his own opinions and those of the Lord, and by making the distinction explicit was signaling to his readers that they should treat the injunctions differently--as if he didn't want to claim for himself the kind of authority that he took to accompany Jesus' explicit teachings.
But if inerrantism is true, then Paul's teachings are the inerrant word of God, and so have the same kind of authority as Jesus' words. In other words, if inerrantism is true, then Paul was wrong to make the distinction he made. But that distinction is made by Paul in a letter that's in the Bible. And if inerrantism is true, a distinction made in a letter that's in the Bible has to be accurate. But if it's accurate, inerrantism isn't true. Zounds!
An exercise in creative interpretation might offer the inerrantist the wiggle room to escape this logical trap, but inerrantists are routinely skeptical of such creative interpretation of Scripture. At best, then, this amounts to a difficulty for inerrantism, the sort of difficulty one often sees when trying to force a theory onto subject matter that doesn't quite suit it. Theories can perhaps weather some such difficulties, but if they become too common it is hard to reasonably persist in endorsing the theory.
4. Efforts to overcome apparent contradictions in Scripture lead to a false view of Scripture
Speaking of difficulties of this sort, the Bible isn't a neat, orderly, systematically consistent treatise. The Gospel narratives, for example, aren't identical. They tell the stories of Jesus' life in different ways. Details differ--for example, in accounts of the resurrection. Bart Ehrman does a fine job of cataloguing many of these in Jesus, Interrupted: Revealing the Hidden Contradictions in the Bible.
Mostly, these tensions aren't explicit contradictions but rather what might be called apparent ones: they don't seem as if they can go together, because you'd need to tell a rather convoluted story to make them fit.
Inerrantists have not been remiss in offering such convoluted stories. But if you need to tell enough of them in order to make your theory map onto what it's supposed to explain, the theory becomes increasingly implausible.
And there's another problem, one that should be of concern to Christians who care about the Bible. The convoluted tales that you have to tell in order to make disparate biblical narratives fit together end up leading you away from an honest appreciation of the message of the biblical authors. As Ehrman puts it, "To approach the stories in this way is to rob each author of his own integrity as an author and to deprive him of the meaning that he conveys in his story."
When you do this, you care more about preserving your theory about the Bible than you do about understanding and taking in its message. For me, this is one of the greatest tragedies of an inerrantist approach to Scripture: It makes it difficult for readers to engage with the Bible on its own terms. It's like someone who is so devoted to a false image of their spouse that they can't see their spouse for the person they really are. Likewise, the steps that need to be taken in order to preserve the doctrine of inerrancy in the face of the Bible's actual content means that it becomes impossible to have an intimate relationship with the Bible as it really is. This is not taking the Bible seriously. It is taking the doctrine of inerrancy seriously at the expense of the Bible.
5. God is love
Christianity teaches that God is love. In fact, it is the closest thing Christians have to a scriptural definition of God: "Dear friends, let us love one another, for love comes from God. Everyone who loves has been born of God and knows God. Whoever does not love does not know God, because God is love." (1 John 4:7-8).
If God is love, then we experience God when we love. If God is love, then the primary way we can encounter God is through loving and being loved--that is, through cultivating loving relationships with persons. This may help to explain the Christian view that a person--Jesus--served in history as God's fundamental revelation, rather than a book. Books can't love you. And you can't love a book in the sense of "love" that Christians (and the author of 1 John) have in mind when we say God is love.
When we feel the profound presence of the divine showering love upon us--or when we feel the joy of being loved by others--we are encountering the divine nature as something coming to us from the outside. But when we love our neighbors as ourselves, we are channeling divine love, and experiencing it "from within" (so to speak). The divine nature is moving within us, more intimately connected to us than any mere object of experience. I think this is what the author of 1 John means when he says that whoever does not love does not know God. To love others is to be filled with the spirit of God. It is to let God in.
If any of that is true, then it is by encouraging us to love one another that God makes possible the most profound revelation of the divine nature and will. And while the Bible does encourage us to love one another, the theory about the Bible which takes it to be the inerrant revelation of God may actually be an impediment to love.
We end up focusing more attention on the Bible than on our neighbors. We are more committed to "doing what the Bible says" than we are to loving those around us. Out of a desire to be connected with God, we insist that homosexuality is always and everywhere sinful--and when the gay and lesbian neighbors we are supposed to love cry out in despair, their lives crushed by these teachings, we stifle our compassion, shutting out love in fear that loving them as ourselves might lead us to question the inerrancy of the Bible.
If God is love, then any theory of revelation that tells us to find God by burying our noses in a book is a problematic theory. If God is love, we must look for God in the love we see in the world. The Bible, understood as a flawed and finite human testament to the God of love working in history, can be a deeply meaningful partner in our quest to encounter God and live in the light of divine goodness. But as soon as it is treated as inerrant, it is in danger of becoming a bludgeon used to silence those neighbors who want to share experiences that don't quite fit with this or that verse.
The Bible points away from itself. Respect for it demands that we look up from the page and engage with our neighbors and the creation. God is alive in the world. The Bible tells us that God is alive in the world. In so doing, the book is telling us that if we want to find God, we need to look into our neighbor's face with love, and at the natural world and all its creatures with love.
Because God is there. God is there, revealing Himself in the vibrancy of life and the child's laugh and the mother's tender kiss. God is there, in the gay man who sits by his longtime partner's hospital bedside, gently stroking his brow. God is there, in the joyous wedding vows of the lesbian couple that can finally get a legal marriage after years together.
And any time a too-literal allegiance to the letter of the biblical text causes someone not to see the face of God in that tenderness and joy, the doctrine of biblical inerrancy has blocked divine revelation, impeding God's effort to self-disclose to the world.