How do we know the bible is 100% real and based on true events rather than a story made by someone(s) with a wide mind and their own religious beliefs? ? (legit educated answers only )

If you really think about itthe bible has been rewritten millions of times over the years so you know things were added to it to make the book longer. Remember when it was first written, it was nowhere near hundreds of pages. It was written in stone lol think about it. I'm not saying the things in it aren't real, I'm just saying they elaborated on it over the years.