Well maybe you could point to the passages in the Bible that discuss that "fallen nature". Otherwise, I will simply consider it more of the Augustinian Gnosticism from his Manicheism background that he introduced into his theology.
Inherited sin is that sinful state into which all people are born.
Theologians have used several labels to describe this concept. (1) Some call it, as the title of this chapter, inherited sin. This emphasizes the truth that all people inherit this sinful state from their parents, and their parents from their parents, all the way back to Adam and Eve. (2) Others call it the sin nature, which focuses on the fact that sin has corrupted our entire nature. The term “sin nature” provides a clear contrast between that root nature and its fruits (which are particular acts of sin). (3) Still others prefer the term “original sin” because Adam’s original sin produced that moral corruption of nature that was transmitted by inheritance to each succeeding generation.
II. SCRIPTURAL EVIDENCE
The Bible clearly states that all aspects of man’s being are corrupt. “By nature” we are children of wrath—that is, objects of wrath (Eph. 2:3). By actions we are also objects of God’s wrath, but this verse refers to something innate. Psalm 51:5 indicates that this is something we have from conception, not something acquired by actions during our lifetimes.
Every facet of man’s being is affected by this sin nature. (1) His intellect is blinded (2 Cor. 4:4). His mind is reprobate or disapproved (Rom. 1:28). His understanding is darkened, separated from the life of God (Eph. 4:18). (2) His emotions are degraded and defiled (Rom. 1:21, 24, 26; Titus 1:15). (3) His will is enslaved to sin and therefore stands in opposition to God (Rom. 6:20; 7:20).
III. TOTAL DEPRAVITY
The scriptural evidence provides the basis for what has been commonly called total depravity. The English word “depravity” means perverted or crooked. It is not used in the translation of the King James Version, but some modern translations do use it to translate adokimos in Romans 1:28. This word means “not standing the test” and gives us a clue as to how to define the concept of depravity. Depravity means that man fails the test of pleasing God. He denotes his unmeritoriousness in God’s sight. This failure is total in that (a) it affects all aspects of man’s being and (b) it affects all people.
Negatively, the concept of total depravity does not mean (a) that every person has exhibited his depravity as thoroughly as he or she could; (b) that sinners do not have a conscience or a “native induction” concerning God; (c) that sinners will indulge in every form of sin; or (d) that depraved people do not perform actions that are good in the sight of others and even in the sight of God.
Positively, total depravity means (a) that corruption extends to every facet of man’s nature and faculties; and (b) that there is nothing in anyone that can commend him to a righteous God.
Total depravity must always be measured against God’s holiness. Relative goodness exists in people. They can do good works, which are appreciated by others. But nothing that anyone can do will gain salvational merit or favor in the sight of a holy God.
IV. THE PENALTY CONNECTED WITH INHERITED SIN
The penalty that is particularly related to inherited sin is spiritual death. Death always indicates a separation of some kind, so spiritual death means a separation from the life of God in this present life (Eph. 2:1–3). If this condition continues unchanged throughout life, then eternal death or the second death follows (Rev. 20:11–15).
Cut flowers well illustrate living human beings who do good things but who nevertheless are spiritually dead. Is the blossom that has been cut from the plant alive or dead? At first it is beautiful and fragrant, and in combination with other cut flowers, it may grace the finest home, church, or occasion. It looks alive; it is useful; but it is in reality dead, for it has been severed from the life of the plant that produced it. At this point the illustration breaks down, for it is not possible to give the flower new and eternal life, something God can do for the one who believes in the Lord Jesus.
V. THE TRANSMISSION OF INHERITED SIN
The label itself indicates how original sin is transmitted from one generation to the next and the next and the next. We inherit it from our parents as they did from theirs, and so on back to the first parents, Adam and Eve. After they sinned they could only propagate after their kind; that is, their children were sinners by birth (Gen. 4:1; Ps. 51:5; Rom. 5:12). This means that everyone born into this world is a sinner. No one is born good, nor is anyone born partly good and partly sinful. All are equally sinful in God’s sight. If this were not so, then those who were, say, only 50 percent sinful would need only 50 percent of God’s salvation.
Charles Caldwell Ryrie, Basic Theology: A Popular Systematic Guide to Understanding Biblical Truth