There are many different ways to read the bible. Mainly, the bible is not a literal instructional manual unless you are a fundamentalist. And fundamentalists suck. For others, it's a written record of humanity's relationship with God. It's also a collection of writings from a number of different authors and genres - it has history, poetry, letters, and so on. The old testament was written by people thousands of years ago who had an imperfect understanding of God, nature, humans, society, etc.

In large part, the story of Jesus demonstrates how we should reject those archaic rules of our ancestors and act according to very simple principles; nonviolence, love for God, and love for all humans.