That's true and I'll explain below why. But actually there are things that are imperative and there are things that are not.
Of course it's not literal from cover to cover that is silly. The Bible is literally a mixture of figurative language and literal accounts throughout the entire book it doesn't have to be one or the other it is both, when you get to the Gospels the style changes a bit of course, but Jesus uses a lot of parables and illustrations to convey spiritual points. How to tell the difference though between literal and figurative? sometimes it's obvious and other times not so obvious (because many times stories are used to convey specific images or underlying principles, so it may come across as a literal story with real people), the main thing would be to use common sense, another way is who cares? it's not going to make any difference in the grand scheme of things as far as beliefs go or whether or not you interpret an account as metaphorical or actual. When you get to the meat of the Bible and what is to be actually applied that's where it matters. I tried to explain this in the other thread in the topic of resurrection, things that are applicable are things that one can apply to themselves. You can't apply what can't be applied, what is to be believed is different than what can actually be applied.
For example, I can "believe" that Jesus rose from the dead but I can apply "Set your affection on things above, not on things on the earth"....or " For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting".....or another example...." Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind" ect ect there are literally endless spiritual principle that can be applied and have direct results. There are beliefs and then there is application, and only one of those things merits growth of the individual.
But back to the point, the opening Genesis account is obviously symbolic and figurative which conveys layers of meanings. A talking snake for example would be a good clue, God needing to take a nap (rest) after creating for six days is another lol.....those are obviously silly when rendering a literal interpretation. The trick is, there could be literal elements within any given figurative style of writing. The Bible literally weaves in and out of figurative and literal. I've been reading the Bible on my own since I was a kid so to me it's very simple to get but people want to make it much more complicated. But the plain truth of the matter is that it doesn't really matter, if you use good common sense and you apply what it is that needed then you have everything you need. In the end nothing will change if you decide to believe in the Noah's Ark tale, but it will make a difference whether or not you applied teachings and principles. Principles are things you actually work out within yourself, it may apply to how you live, think or act or even feel. These are the things that you want to take seriously and what makes you either a God-lover or not.
The Genesis story was meant to convey imagery by using very exaggerated hyperbole statements, it's more like an idea or a picture of creation rather than the literal way God created the universe. It was never meant to be a science journal, rather meant to invoke simplistically the idea of creation, mixed with symbolic overtones. The snake for instance is meant to convey the nature of temptation, not that there was literally a talking serpent. And even though God thought within God's mind and desires "let there be light" that's not how God brought into existence light within the universe.
There's a process involved into manifesting things into existence and Genesis skips through those processes. Rather it just gives you some imagery to ponder on, not to mention it would be very boring and tedious if the creation account was to be articulated in a scientific way, too long to read through. This way even a child could have fun reading it, and the funny thing is...as a child when I read it, it made perfect sense, at least to me.
The Bible is a spiritual book, that is what its main focus is. To argue over silly things like is it supposed to be literal is to miss the point behind it. Spiritual books are weird that way, they are like those painting you see where it has a scattered design but when you focus in for a minute a very clear image comes out. I forget what they call those, but anyways scripture and figurative language is much the same way, you have to read between the line or notice the underlying message.