The Bible is the story of the Jewish people's struggle to understand their God. That they made mistakes along the way, and that their concept of God evolved over time, does not imply that fails as a guide. That it is not inerrant does not pose a problem.
If anything, it is the assumption of inerrancy that poses the greater problem. For those who believe inerrancy must accept that their God is massively confused, is at times evil, and is highly inconsistent.