I Don't Understand His Argument on Original Sin

I was listening to his ah. He does a sunday, a defender's class, his sunday scool class that he teaches every sunday. And i've listened to lots of that, and there was one really interestingAh, he does this every year, so there's several, you know, times he's gone through and done all this. But there there was one episode where he went through the doctrine of original sin and basically said he doesn't think aoriginal sin can be extrapolated from the bible. I do not understand his argument on this anyway. It just seems like such a strange move to say why.