Total Depravity

Here's how John MacArthur responded to the notion of innate human goodness:

False belief systems always seem to downplay human depravity. Some even deny it altogether, insisting that people are fundamentally good. This is a tendency of nearly all quasi-Christian heresies, humanistic philosophies, and secular worldviews. Apostles of those religions and philosophies seem to think describing human nature in upbeat and optimistic terms somehow makes their viewpoint nobler. That fact alone perfectly epitomizes the blind illogic that goes hand in hand with unbelief and false religion. After all, humanity's moral dilemma should be patently obvious to anyone who seriously considers the problem of evil. As G.K. Chesterton famously remarked, original sin is the one point of Christian theology that easily can be proved empirically.

The fallenness of the human race is a profound, destructive, and universal predicament—inexplicable by any merely naturalistic rationale, but undeniably obvious. Wherever you find humanity, you see ample evidence that the entire race is held captive under sin's corrupting influence.