I’m not calling the Bible nonsense - I’m giving my interpretation of it. No one has to agree with me, obviously. As for a reason for existence, I see the answer to that question simply as God. God IS existence, and our reason for existing is to seek God.
Maybe that’s too simplistic, but it works for me.
You’re still at the stage where you’re dealing with “God as a theory.”
I used to do that, until I met “God as a person.”