Fred Clark gets it:
One of the first questions when approaching the subject of human nature tends to be are we essentially good or essentially rotten? The Christian answer — “Yes!” — can seem like a cop-out, or a contradiction, or a paradox (the euphemism theologian’s use for those contradictions we like). The idea is that every human is of inestimable worth, bearing the very image of God through and through. Yet every human is also fallen, broken, corrupt, through and through. And the matter of virtue and wickedness is only part of the equation anyway — we’re not just fallen, but also finite, fallible and fragile.