The biggest mistake the Christian church has ever made is throwing out the OT. We've lost our heritage and the context of our faith.
"Progress"--that's what society calls the process of abandoning God's wisdom for human understanding. We'll be a great society when we learn to progress as a society without losing our heritage and understanding. God gave us wisdom and we have thrown it out because we chose not to put forth the effort to discover it. He told us certain things will bring destruction and we ignore Him.
I'm reminded of my three year old who argued with me when I told her where milk came from. It made no sense to her that it came from a cow so she didn't believe me. She was sure milk came from the fridge. Society has done the same thing. We had perfect wisdom and we threw it out because it was too difficult to understand. We threw out the God idea because we had no understanding of Him and chose to believe that unless we understand it, it doesn't exsist. Unless we see the consequences, it has none. We think we are our own creation, the world just invented itself. That's no less laughable then the fridge producing milk. Except, unlike my then three year old, we're gambling our eternity on it.