So the NT says nothing of the sort. What the NT says (or rather, what Jesus is supposed to have said in the Sermon on the Mount IIRC) is that he fulfilled the law. Does that mean the law no longer has any relevance? If so, then what the hell is the OT doing as part of the bible? I know how it became a part of the bible historically, but why if it's now fulfilled and fulfillment means 'no longer necessary' is it still there? I don't know how you can have it both ways. Either the law is fulfilled and is no longer important and shouldn't even be mentioned in Christian theological conversations, or it's still important and Christians just ignore the parts they don't like.
I have an alternative theory: Christians have beliefs that are largely a product of their culture and upbringing, and they utilize the bible in whatever way they see fit to provide divine authority for what they already believed. Which they then, from time to time, use as a club to try and beat down those they disagree with and justify all manner of lunacy like teaching creationism in public schools.
As for me claiming some special status for my interpretation of the bible, I don't interpret the bible in anywhere near the same sense Christians do. I don't care at all about the bible as a guide to living morally or achieving salvation, I only look at it in reference to the ideas and actions of Christians. The only dog I have in this fight is my strident opposition to Christians imposing their religious views on others, and if pointing out internal contradictions in the bible and the hypocritical ways in which Christians leverage scripture to oppress people weakens their arguments I'm happy to do it.