Even if the ancients happened to write 'God said unto to David....' or 'the Lord inspired David' it does not mean that God actually spoke to David or the Lord actually inspired David or anyone, or that there is indeed a Lord God...but just another claim being made by the author of the narrative. They wrote a lot of stuff that is quite frankly absurd, but it is what one would expect from that time, place and culture.
The odd thing is that this bronze age religious world view has survived into a time when we should have a better understanding of the needs and motives that produced these beliefs in the first place, and not just accept them on face value because they may be appealing. A bit of healthy scepticism is required.
The real world is far vaster, complex and more mysterious than anything you can possibly find in the bible, or any of our so called holy books. They all pale into insignificance to the real Universe, like a baby attempting to capture a sunset on an autumn evening scribbling with crayons....
