Those who deny the doctrine of Depravity are foolish and have not read their Bible. The doctrine was not invented by Calvin but only brought forward and systematized by him. History tells us that this doctrine really impacted the American Founding Fathers. That is why they developed the three branches of government because they realized that because of the sinfulness of man, there needed to be checks and balances in the system of running the nation.
There are many verses that point out depravity, such as 1 Corinthians 2:14. Paul writes "a natural man (the lost) does not receive the things of the Spirit of God; for they are foolishness to him, and he cannot understand them, because (those things) are spiritually understood." "Even so the thoughts of God no one knows except the Spirit of God" (v. 11b).
Christ spoke almost the same thing in John 14:17. "The Spirit of truth the world cannot receive because it does not behold Him or know Him ..."
-- Dr. Mal Couch (7/11)