"The heart is deceitful above all things and beyond cure. Who can understand it?" (Jer. 17:9, NIV).
"All of us have become like one who is unclean, and all our righteous acts are like filthy rags; we all shrivel up like a leaf, and like the wind our sins sweep us away" (Isa. 64:6, NIV).
"'Come now, let us settle the matter,' says the LORD. 'Though your sins are like scarlet, they shall be as white as snow; though they are red as crimson, they shall be like wool'" (Isaiah 1:18, NIV).
"The heart is deceitful above all things, and desperately wicked: who can know it?" (Jeremiah 17:9, KJV).
"I see better things and I approve them but I follow the worst."--Ovid We are prone to play the "let's compare" (cf. 2 Cor. 10:12) game and suit ourselves by looking down on our fellow man as our inferior who doesn't measure up. As long as we can find someone worse than us we feel secure in our "holiness" or inherent goodness. After all, many of us believe God grades on a curve! Compared to the likes of Adolf Hitler, the paradigm of evil incarnate, we appear to be saints and godly enough to feel smug and self-satisfied in our goodness. But our goodness is from God and not our gift to Him, but His gift to us. Our goodness doesn't benefit God, but we are mere vessels being used for His greater good and glory, whether of honor or dishonor, we are manipulated and used by God's providence. This is a never-ending comparison and relativity since there's always someone we can thumb our nose at, no matter how wicked we are--even in the prisons there are self-righteous bullies who think they are the moral center of the place. We are all in jail, in a sense, but do not realize our depravity and need of a way out and salvation through a Savior. We cannot set ourselves free, and we weren't born free, but in bondage and slavery and can only be unbound by the power of the cross. "... Where sin abounded, grace abounded much more" (Rom. 5:21, NKJV). John Bunyan wrote Grace Abounding to the Chief of Sinners to expound on this motif.
How bad are we? Metaphorically, we are as far from God as a blind person comprehending the beauty of nature and hearing a symphony, if one is deaf. God is in another dimension and we are God-conscious and feel a tug to know He's there by instinct. No one has an excuse not to believe in Him and God's knowledge is plain to all. We must realize how bad we are to be good, according to C. S. Lewis, and we don't realize how bad we are till aim to be good. It's like thinking you can quit tobacco anytime, but when you try to quit you can't because it's got more power over you than you realized. We don't have the freedom of will to cease sin on our own, but are slaves to our sin nature and need to be set free by the Son (cf. John 8:36).
According to the doctrine of total depravity, we are as bad off as we can possibly be: every part of our nature is corrupt and affected adversely by evil and sin, including our emotions, mind, will, and body--all that we are. As far as our will goes, we are stubborn and hard as a stone, and God must turn our hearts into ones of flesh (cf. Ezek. 36:26). We don't think clearly because of sin and are blinded by Satan to the truth of the gospel. Our emotions are attuned to the lower nature and have lost their purity. Our bodies are dying and do not bring glory to God either apart from grace, no matter how well we treat them. In sum, we are bad, according to D. L. Moody, but not too bad to be saved! We all have feet of clay; we all are a Dr. Jekyll and Mr. Hyde--we all have a dark side no one sees.
The qualification for receiving eternal life is to realize you can't qualify! "Therefore I abhor myself And repent in dust and ashes" (Job 42:6, NKJV). We can't earn our salvation, we cannot pay it back, and we don't deserve it either. We cannot rationalize our way back to God by philosophizing or thinking; we cannot moralize our way back by good deeds, and cannot emotionalize our way back by our feelings. We must be sincere, but sincerity is not the whole equation, we must be willing to do God's will and repent of our sin, renouncing and denouncing it, in order to follow Christ in obedience and trust. God has reckoned all to be dead in sin so that He can have mercy by grace on us all. We don't get saved because of our intelligence, morality, emotions, wisdom, or even philosophy--or any accompanying affiliation or party membership. We must not deify a person, group, or even party, for this is idolatry.
We must echo the wise words of William Jay of Bath, who said that he is a great sinner, but he has a great Savior. It is only in realizing that we are sinners and are spiritually bankrupt before God that we can value Jesus as our Savior. The closer we get to God, the more we become aware of our shortcomings and sins. Samuel Rutherford said to pray for a lively sense of sin because, the more sense of sin the less sin. Remember the words of George Whitefield: "There but for the grace of God, go I"; which he uttered upon seeing a man going to the gallows. Paul said in 1 Cor. 15:10 likewise: "I am what I am by the grace of God."
This is the point, just because someone seems like a worse sinner than you are, doesn't necessitate him being further from finding God; sometimes the prostitutes and tax collectors are closer to God than the Pharisees of the world. Just because your sins may be more civilized, polite, concealed, or refined doesn't make them less serious: better off the ignorant cannibal in the South Seas than the informed bully on Wall Street! The Greek admonition to know thyself goes hand in hand with knowing God. Why do you think the Law was given? To convince you that you cannot keep it and need a Savior! The Bible tells it like it is; how we are and how God is and how to restore the relationship. Once you've seen your nature for what it is, you'll realize it's not a pretty picture. The closer we get to the Spirit's illumination, the clearer becomes our blemishes.
Note that depravity is not what the world espouses: Secular Humanism postulates the inherent goodness of man and that he can be good without God! All goodness comes from the Source of all Goodness, God, and the definition of evil and temptation of Eve is how to be good without God in the equation, noting that evil is a parasite on good and distorts or perverts it; to find our own values, virtues, wisdom, and enjoyment without God in the picture. Humanism originates from the Greek philosopher Protagoras who said that "man is the measure of all things" ("Homo mensura"); thus exalting and deifying man, and dethroning God as irrelevant and even nonexistent--up with man; down with God, the credo. Their aim is to make a name for themselves and live for this world and life only, thus taking away the motive for reconciling with God. Their conclusion is that no deity will save them and so they must save themselves (cf. Humanist Manifesto II, 1973). Thus, the issue is whether one chooses to believe in himself, or in God for salvation.
Psychiatrists are starting to refer to "sin" again, according to Karl Menninger, MD (who penned Whatever Became of Sin?), and this means he knows right and wrong and is culpable unto Judgment Day. It only takes one sin to make a man a sinner, as violating one part of the Law is an infringement on the whole of it. We are not sinners because we sin; we sin because we are sinners (as theologians say). Martin Luther said that man doesn't see his sin, and it's our job to inform him. When Paul said that "all have sinned," he was putting us all in the same boat, with no grading on the curve--we all have been put under the scrutiny of God and found wanting. Caveat: "... Your sins have been your downfall" (Hosea 14:1, NIV); "...[S]in lies at the door. And its desire is for you, but you should rule over it" (Gen. 4:7, NKJV).
The worst sinners are those who are confident in their personal righteousness and see no sin; the self-righteous, goody-two-shoes sinners of the world. It is vital to realize our sinfulness because it implies our responsibility and helplessness before God and smashes our sense of self-righteousness and shows our rebellion. Many must first realize they're lost and need salvation as a requisite for getting saved from sin. Trusting in your own intrinsic goodness leads to death, for God is the moral center of the universe and the final Judge will meet one-on-one with everyone to give an account of themselves. In sum, let me emphasize that it's not that we are good enough to get saved, but bad enough to need salvation. There's hope for everyone. DON'T WRITE ANYONE OFF AS TOO FAR GONE!
Soli Deo Gloria!