What do you mean a Coherent back story?
Ever read a work of fiction? The story you read is essentially only as “old” as the actions of the characters, IOW the story’s main timeline. That’s the one in which the characters act. However, there is often a “backstory” that explains events that came before. Any good author makes sure the backstory - the actions that happen before the main timeline - is coherent with the main story.
Now, writing a work of fiction is an act of creation. So wouldn’t it make sense for the First Creator - God - to be able to do something similiar with His story, our reality? Thus, when He created the Earth and everything else, maybe He gave it a backstory, which from our perspective is entirely real. And of course His backstory would be perfectly coherent (ie, without contradiction to the main story).
In Bible-like terms, this would be “God created the heavens and the Earth, along with histories for them.”
Just an idea I toy with, not an advocate of it. But it does seem to explain a lot.