If by 'depravity', you mean 'the innate corruption of human nature, due to original sin', this would also mean one must reject a fairly large scientific theory. Well, I've studied such a scientific theory and believe it is true, due to evidential accounts. Belief does not validate that the belief is correct; just that one believes it. So even if my belief is false, I still believe it. But the conclusion of this belief means I have no choice but to not believe in the concept of 'original sin'. And since belief is the primary tenet in Christianity, I guess I'm screwed, if actually true.
However, luckily, it would appear that whoever wrote the Bible did not appear to have a clear grasp on reality (at least from my estimation).
Is it my inherent depravity which makes me conclude this scientific theory correct, which makes me then also conclude, using intellectual honesty, that I can not longer accept the claim for 'original sin?'