Arthur Pink gives an outstanding explanation of total depravity in his book The Total Depravity of Man. You can download a free e-book of this excellent work on the link given. Here are a few excerpts:
It is a sadly neglected subject. Notwithstanding the clear and uniform teaching of Scripture, man’s ruined condition and alienation from God are but feebly apprehended and seldom heard in the modern pulpit, and are given little place even in what are regarded as the centers of orthodoxy. Rather the whole trend of present-day thought and teaching is in the opposite direction, and even where the Darwinian hypothesis has not been accepted, its pernicious influences are often seen. In consequence of the guilty silence of the modern pulpit, a generation of churchgoers has arisen which is deplorably ignorant of the basic truths of the Bible, so that perhaps not more than one in a thousand has even a mental knowledge of the chains of hardness and unbelief which bind the natural heart, or of the dungeon of darkness in which they lie. Thousands of preachers, instead of faithfully telling their hearers of their woeful state by nature, are wasting their time by relating the latest news of the Kremlin or of the development of nuclear weapons.
It is therefore a testing doctrine, especially of the preacher’s soundness in the faith. A man’s orthodoxy on this subject determines his viewpoint of many other doctrines of great importance. If his belief here is a scriptural one, then he will clearly perceive how impossible it is for men to improve themselves—that Christ is their only hope. He will know that unless the sinner is born again there can be no entrance for him into the kingdom of God. Nor will he entertain the idea of the fallen creature’s free will to attain goodness. He will be preserved from many errors. Andrew Fuller stated, “I never knew a person verge toward the Arminian, the Arian, the Socinian, the Antinomian schemes, without first entertaining diminutive notions of human depravity or blameworthiness.” Said the well-equipped theological instructor, J. M. Stifler, “It cannot be said too often that a false theology finds its source in inadequate views of depravity.”
For most people, when the word sin is spoken, it is used either in a metaphorical sense or applied to people like Bernie Madoff, Hitler or Stalin, or used for exaggeration purposes, depending on the situation. When we consider our bad behavior or even the intentional harm we’ve caused others, we think of these things mainly in terms of mistakes, accidents or wrongs toward other people in particular … but sin? No, we’re not that bad! (Being facetious of course).
As I have been reading through Genesis the past couple of weeks, something has become clear to me as the story line has progressed. We all know the story of Jacob and Esau, well, at least some of you reading might. As Paul says and properly interprets of this story in the latter part of Genesis, particularly as he says it in Romans 9:10-13, “When Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad—in order that God’s purpose of election might continue, not because of works but because of him who calls— she was told, ‘The older will serve the younger.’ As it is written, ‘Jacob I loved, but Esau I hated.'”
Interesting … science backing up the Scriptural, spiritual reality of our hearts. We are sinful from birth, even from the time our mothers conceived us, just as David says in this Psalm. Well, we at least begin lying at six months old, as this article states. Before this study, it was thought babies did not lie prior to 4 years old. Now the bar has been lowered to six months. This study simply confirms that which is stated in the Scriptures: we are sinners from the womb. Our disposition, from the very beginning, is bent on evil, namely a suppression of the glory and righteousness of God. We must be delivered from this very nature by the work of Christ alone in order to even see Christ at all as worthy of our praise. The only difference between a grown up and a baby is that the adult has the means to carry out the wickedness that lies within the heart. Babies can’t talk in tangible language, they have very little strength to exert, but they can throw tempter tantrums, scream until they get their way, and as shown in this article, they have scientific proof babies begin conceiving deception in their hearts as early as six months. As cute as babies are, this is the reality of all of us and it starts at conception (just as the Psalm said). “It is hard to exaggerate the importance of admitting our condition to be this bad.” (Piper) We must be saved utterly by the work of God in Christ to deliver us from the deadness and nature of our hearts that are turned away from the glory of God. It is by grace alone (God granting regeneration, repentance, and faith) through God-wrought faith alone, in Christ alone that we are saved. Praise God for His mercy and may He move on my daughter Adelaide to turn her heart from the natural deadness that lies within, turned away from God, and draw her to Himself. May He raise her up, by His pure mercy, even now, and grant her regeneration unto salvation. We are prone to wander unless God holds us back by His mercy. This verse and this science both show this to be the case.