Imagine that your friend Tom ran up to you and frantically blustered out, "Mike said that an angel revealed to him the date of the apocalypse - we have to leave the country and form a colony in the middle of the Pacific. It's our only hope!" You might dismiss the comment out of hand, for no particular reason other than that it sounds unlikely. But that's not a good reason to dismiss it. Let's say you go to question Mike, and you ask "Why the Pacific?" Mike confidently tells you that there's a mountain in the middle of the Pacific Ocean, and that if we all climb to the top of that mountain we'll be spared from the apocalypse (presumably a flood) and live. So you threaten to kill him, stabbing him through the shoulder once to show him you're serious. He still won't recant - he believes what he's saying is true. You still won't follow Mike because you've checked Google Maps and there is no mountain in the middle of the Pacific Ocean.
You go back to Tom and tell him everything. Tom looks at you kind of condescendingly and says, "______, you're too much of a literalist. I know Mike is wrong about the mountain in the middle of the Pacific, but I believe him on spiritual matters." Mike is dangerously wrong, and Tom is an idiot. Why? And what does this have to do with Liberal Christianity?
Why Tom Is Like Liberal Christianity
In the example, you can't check whether the apocalypse is coming, but you can double-check whether Mike is really trustworthy on the subject. But if Mike fails on the things that you can prove (or disprove, as in this case with the mountain in the Pacific), Tom is a fool for trusting Mike on the things that can't be proven (like the apocalypse or the angel). Tom is anti-intellectual; he chooses to keep believing when he has no reason to do so. Tom even admits that Mike is wrong about basic facts, and he still won't give up following Mike.
Liberal Christianity is just about as dumb and anti-intellectual as Tom. It really believes that the Bible has failed on the factual stuff (historical details, science, failing the test of non-contradiction), and it still says incredibly laughable things like "We still believe the Bible on spiritual matters." That's crazy. Why would you believe a book on an unprovable subject when it has supposedly failed every test that can be thrown at it? Liberal Christianity thinks it's enlightened because it's kept the beliefs, and thrown out all of that small-minded literalist stuff. But it has no reason to hold to Christian beliefs, any more than you or I have reason to believe in fairies or the Flying Spaghetti Monster (followers of whom declare themselves to have been "touched by His noodly appendage"). They believe a book which they also believe has been disproven on every other issue. With that kind of standard, next they'll be drawing their beliefs about Jesus from Tom Harpur's thoroughly debunked book Pagan Christianity (woops, some non-Christians already do).
Plenty of Reasons to Believe the Bible
That said, there are plenty of reasons to believe in the Bible. Liberal Christians think that the Bible contradicts itself, but I'm addicted to reason and even I haven't found a contradiction that holds. Liberals think that the Bible doesn't fit with historical knowledge, but archaeological finds overturn that opinion every other year. The accepted dates for Biblical writings just keep getting earlier and earlier. The writers of the New Testament believed their message so much that they died for it. Not only that, but no one even contradicted their facts until hundreds of years later. I can't double check what the Bible says about the Trinity, or salvation, or angels and the apocalypse, but I can check what it says about other things. And if it fails to prove that it's trustworthy, if the writers fail to prove they were trustworthy, then you and I have no reason to be Christians. There is no such thing an intelligent, non-literalist, I-believe-the-Bible-only-on-spiritual-matters Liberal Christian faith. The only intelligent faith options are literalist, Bible-believing Christianity, or agnosticism.
Not Heaping Scorn On Liberal Christians
My hope? Not to heap scorn upon liberal believers, but to show them that their position doesn't work. I've been reading Richard Dawkins' The God Delusion, and all I keep thinking is, "Wow. That's a really good argument against non-literalist Christians." Dawkins is right. The kind of faith that some Christians -liberal Christians- hold to is no more believable than trusting in Wotan or the tooth fairy. If the Bible contains errors, contradicts itself, and isn't historically trustworthy, then it can't be trustworthy on spiritual matters either. Ditching the Bible and holding to the faith isn't really a well thought-out, intelligent option.