The simple answer: no one knows.
The Bible was written by many people over a long period of time. It did not fall from the sky as a completed book. The path it took from text to canonization remains a mystery.
But there are some pretty good theories. These are based on educated guesses, slim pieces of historical evidence, and theological assumptions.
Does it matter how old the Old Testament is? Maybe what matters more is, when and how do we have the discussion about this question? The answers we discover (and choose to believe) affect our theology, our ethics, and our politics.
How old is the Old Testament? Simple question. Complex answer. Let’s talk about it.