Not the poster, but as a Christian, no, I find the idea of the Bible being taken literally as rather surprising, and a rather recent invention.
Just on the face of it, there are 'books' in the Bible meant as history, books meant as 'self-help', despondent mullings on the meaning of life, a love letter, personal recountings, letters written to others...these are all kinds of authors and approaches here, and so it strikes me as silly to take all of them literally. I mean, Jesus is quoted as saying "Go tell that fox", when speaking of Herod; there is no other mention of Herod being anything other than human. Clearly, if the Christian message is to be taken as truth, it shows that God is able to speak in metaphor (as well as interesting translation differences; for instance, the word for 'day' in the creation story is a word with a number of translations ( https://en.wikipedia.org/wiki/Yom )
So, how do things that seem antiquated apply now? Well, some parts of it -are- antiquated, in that they were meant for a specific time, and not now. Chesterton had a number of beautiful assertions in his book Orthodoxy, to the effect that Christianity is necessarily paradoxical, because -people- are paradoxical. To take that here, from my perspective (and there are many) morality can be both absolute and relativistic; what is 'good' is absolute, but what is treated as 'good' at a given time is relative to that time. You know that slavery is evil, but could you go back 4000 years and convince people of that? No. You would just alienate them, and likely get yourself killed. But you -could- convince them to at least treat their slaves better. You could design a moral code that would in time lead to them stopping slavery, by just introducing the idea that slaves are humans, with rights. If we credit the idea there is a God, and that evolution is a thing that that God uses, then the idea of allowing a moral idea to evolve into a fuller fulfillment of itself, over time, as people think, and talk, and develop, is an unsurprising thing for that God to do.
As to stoning adulterers, and a number of similar things; don't misunderstand what was a legal code with a moral one. Yes, it was influenced by morals (same as our own law is), but the punishment was a legal code to be adopted by a people, and was a symptom of the time. No Christian but the most fundamental would say we, now, should adopt stoning as the appropriate punishment for adultery. Interestingly, the Bible makes it clear "the wages of sin (is) death", but that that's a moral issue between man and God. Any actual judgement indicated to be carried out between men is toward a legal system, and its rationale is much the same as our own, to prevent people from doing it and/or to allow for carrying out some semblance of imperfect justice (since flawed man judging flawed man will necessarily be imperfect).
Similarly, many of the Old Testament rules were particular to the context of the time, and can only be understood in understanding the culture at that time. For why not wearing a diverse set of fabrics, have a look here - https://www.gotquestions.org/different-types-of-fabric.html