Well, you could decide not to teach evolution, even though it has become generally accepted that there is enough evidence to make it plausible (I'm not talking Darwin's theory, but "the theory of evolution" as is now taught in schools. But, I hardly see creationism as the reason for that. It has
zero evidence at this stage.
I agree with you RE the reason for the bible - not that I believe in god, but what the book is supposed to be about
OK - the flood bit of the bible - If the bible said "in 1243 BC, there was a flood that went on for 40 days, and the entire population of
river valley X was wiped out except Noah", then that might be evidence. This is not the case. You could also say (probably correctly) that the bible contains true historical references by using other historical texts to show that there was a flood around the time that the bible was written. This does not extrapolate into the bible being evidence in its own right.