All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God may be thoroughly equipped for every good work.
Scripture is the written word of God. Every line, and every word is important within it. Of course it’s not flat. It has to be read in context, and from Genesis through Revelation as a story, essentially the story of God. We understand this from scripture itself, and from Jesus’s witness to it. Jesus considered scripture to be God’s word, of course Jesus himself being the Word, just as scripture says.
We don’t pick and choose what to believe and what not to believe, but we do read scripture in context. And in so doing, we find that new light does bring changes both in people’s understanding, and actions. As well as a new day dawning when Jesus appears with the kingdom of God in him being at hand.
But all of scripture is God-breathed and useful. So we need to be committed to reading all of it, and praying through it. And understanding it through its fulfillment, Jesus. And where we live now as followers of him.