What does the Bible teach? Well, depending on your reading of it, just about anything you want it to teach. You can find passages that suggest God is loving, while other passages suggest God is full of rage. You can find passages that recommend staying away from alcohol, and others that seem to condone its use. You can find passages that seem to support vengeance toward someone who has wronged you, while others support forgiveness. The list can go on and on. Does this mean that the Bible is a book of contradictions? No more than a parent's words to a toddler compared with the same parent's words to a young adult.
God seems to meet us where we are in our knowledge about life and about Him. There are words in the Bible for people coming from all different places. Only as we read the Bible in this manner will we start to see harmony in all that it says. God never changes, but, due to His gracious influence, we do.
The Bible is a codebook with instructions, laws, counsel and grace for everyone who reads its pages with a heart to know God's will for their lives. The Bible is also like a casebook, showing how God has worked with humanity at many levels and in many circumstances. There are historical narratives, poems, songs, prose, sayings, biographies, pastoral letters of advice as well as prophetic predictions. If we read it as something other than this, then we miss out on seeing how God has used humanity as a conduit for communicating the Truth about Himself to the world.