BackforGood "most Christians realise that the Bible is a massive collection of books, written by many different authors, many of whom weren't alive until hundreds or years after the events they were writing about, "
That by happy chance is my position too. There is no evidence that any part of that is real and no way to know who wrote it. and much of it is primitive tribal laws which you should not take seriously now,
Unfortunately even in the 21st century there are still people who think it was told to Moses by a 'god' and that he told Moses how he created the world and made Adam & Eve.
They think that the Ten Commandments were written by this god and passed down and that he wouldn't have let Moses make rules about killing his people unless he approved.
You can see how it is from their point of view. Without believing in those first 5 books they have no reason to suppose a god created the world at all and there goes sin, hell and heaven along with it.
If they do believe it then they are required to think god hated gay people and unbelievers and went around slaughtering men, women and children whenever he had a tantrum. (See Great Flood, The Slaughter of the Firstborn of Egypt and ... well most of the OT)
If we just accept them as a wandering tribe then we can't blame them for their primitive rules, but if god were real then wouldn't have been primitive back then and becoming more enlightened now would he.
Most Christians seem to think of Jesus saying 'be nice to each other' and that's good. He doesn't have to be god for that to work. You can think of Jesus as being a guy who looked around at a harsh religion/culture and said "we can be better than this"
But people want the reward so they cling on to the god thing and in doing so they support the belief that the bible is from god and that the rules matter.
Then because they support the bible the awful lessons the Old Testament teaches and the atrocities it praises go forward to the next generation.