God: "I looked for someone to take a stand for me, and stand in the gap" (Ezekiel 22:30)
This, then, is the sense in which people are totally depraved: we have all treated God in the most insulting way by registering again and again a vote of no confidence in His promises.
There is nothing in the world that works such satanic, profound, God-defiant pride as false assurance; nothing works such utter humility, or brings to such utter self-emptiness, as the child-like spirit of true assurance.