Bear in mind that I tried my hardest to follow the Bible for many years. I even had the bookmark that says:
God said it, I believe it, and that settles it.
The following response - typed within ten minutes of reading the question - shows how far my attitude to the book has changed. At one time I would have been the one asking the same question to someone like the me who exists at this time.
The book contains many marvelous things and great statements. It contains witnesses to the lives and views of people seeking God and truth and fulfillment. It contains in the Book of Psalms all the range of joy and sorrow that we experience. And it contains witnesses to the life and ways of Jesus and some of the people who sought to follow him and base their life on who they believed Jesus to be.
The Bible contains many "wow" moments and much that is a pointer to a greater life, written by men in their own societies with their own views and walking the spirit path walked by so many others.
But my response this morning shows just how far behind I've left the way of blindly "following the Bible." My view now isn't just that we shouldn't follow the Bible in the way it's often followed - but that "following the Bible" at all is almost an impossibility because of all the assumptions and prejudices we bring to our study and reading of the book.
We can't follow the Bible. Because we cannot answer the question "What is the Bible?" And we cannot answer the questions "Why is the Bible?" and "Why is the Bible in the form it is?" Even if we do manage to remove our own assumptions and approach the Bible dispassionately as a perfect scholar then we cannot - so far - come to any solid conclusions. Hence the often interesting debates and disagreements of skilled theologians.
And if we do not know what the Bible is we can't accurately read what it says and why it says what it says. And we can't say what it means - we can only say what it means to us who bring all our baggage to it. We certainly can't produce any dogma to be applied to everyone else. All we can say is that we can read the book, follow our own inner promptings and the methods we've learned from fallible men, and find some light and direction. Which is a perfectly good thing to do.
Thus I believe that "following the Bible" reveals far more about the follower than about the book. When we follow the Bible we really follow ourselves or follow a preacher who in turn follows theirself or follows another favourite preacher.
So, onto my original response to the question:
Why follow what a book says? It was written by men, edited over many hundreds of years, based on older myths and written to justify points of view. And then interpreted by later men to justify their own prejudices. It is a book about a story. It's not an infallible and clear guide to life. And it contains some quite frankly obnoxious and offensive things. (Not just the supposed gay things - things like an unmarried rape victim having to marry the rapist, like God approving of genocide, like God approving of murdering children for taunting a prophet. Lots of things that I don't think we should EVER follow.)
When selling many hundreds of my Christian books on ebay I grew to dislike the word "biblical". Generally it means "justifying my own point of view by using Bible verses" - so entirely contradictory books would be described in the blurb as "thoroughly biblical". (I've probably cleared out about 3,000 of my Christian books and now have less than 1,000 on the shelves - the fruit of too much reading, too much obsessive book buying, too many denominations, too many sermons written and a couple of theology degrees.)
"Follow the Bible" ends up being a nonsense in which people accuse each other of not following the Bible because they disagree with one another. "Our Church is biblical - yours can't be because we're Calvinist and you're not, or you're the wrong sort of Calvinist." I've heard and seen things like that quite frequently.
You (the person who me asked the question, not you who read this) for instance don't agree with gays. That isn't because you follow the Bible. Some gay friends love the Bible - and one has a PhD on the sort of verses and "proof texts" you might quote to gay people. But it's possible you don't agree with gays because of the way you approach the Bible - and because of the way you approach human beings - and because of the preaching you've been subjected to.
Nobody follows a book despite the claims of many. But people follow their own views about what that book is - how much is literal or metaphor or whatever else - and their own views about life, received from parents, reading, experience or preachers.
I am someone who has in the last year been called an evil abomination by people who claim to "follow what the Bible says". Simply because I am who I am - because I am transgender. They pick out verses, rip them from context, misapply them and say it's impossible for me to be a Christian at all unless I repent of being transgender.
If that's following the Bible - as MANY churches teach - then no, we should not follow the Bible.
We should follow love, life, wonder, awe, creativity, beauty, hope, fearlessness, extravagant giving, wisdom, knowledge, intuition, peace. We should follow the path that leads to all these things in the greatest abundance.
If you do that by following a book, and if you don't use the book to crush the spirit of a human being in any way, then that's great. But I can't do that.