Original sin. "Our first parents being the root of all mankind, the guilt of their sin was imputed, and the same death in sin and corrupted nature were conveyed to all their posterity, descending from them by ordinary generation." Adam was constituted by God the federal head and representative of all his posterity, as he was also their natural head, and therefore when he fell they fell with him (Rom. 5:12-21; 1 Cor. 15:22-45). His probation was their probation, and his fall their fall. Because of Adam's first sin all his posterity came into the world in a state of sin and condemnation, i.e.,
(1) a state of moral corruption, and
(2) of guilt, as having judicially imputed to them the guilt of Adam's first sin.
"Original sin" is frequently and properly used to denote only the moral corruption of their whole nature inherited by all men from Adam. This inherited moral corruption consists in,
(1) the loss of original righteousness; and
(2) the presence of a constant proneness to evil, which is the root and origin of all actual sin. It is called "sin" (Rom. 6:12, 14, 17; 7:5-17), the "flesh" (Gal. 5:17, 24), "lust" (James 1:14, 15), the "body of sin" (Rom. 6:6), "ignorance," "blindness of heart," "alienation from the life of God" (Eph. 4:18, 19). It influences and depraves the whole man, and its tendency is still downward to deeper and deeper corruption, there remaining no recuperative element in the soul. It is a total depravity, and it is also universally inherited by all the natural descendants of Adam (Rom. 3:10-23; 5:12-21; 8:7). Pelagians deny original sin, and regard man as by nature morally and spiritually well; semi-Pelagians regard him as morally sick; Augustinians, or, as they are also called, Calvinists, regard man as described above, spiritually dead (Eph. 2:1; 1 John 3:14).
The doctrine of original sin is proved,
(1.) From the fact of the universal sinfulness of men. "There is no man that sinneth not" (1 Kings 8:46; Isa. 53:6; Ps. 130:3; Rom. 3:19, 22, 23; Gal. 3:22).
(2.) From the total depravity of man. All men are declared to be destitute of any principle of spiritual life; man's apostasy from God is total and complete (Job 15:14-16; Gen. 6:5,6).
(3.) From its early manifestation (Ps. 58:3; Prov. 22:15).
(4.) It is proved also from the necessity, absolutely and universally, of regeneration (John 3:3; 2 Cor. 5:17).
(5.) From the universality of death (Rom. 5:12-20).
'Sin' from Eastons Bible Dictionary
By original sin (also called ancestral sin, hereditary sin, birth sin, or person sin), when used as a theological term, is meant the fallen state of humanity. In the history of Christianity this condition has been characterized in ways ranging from something as insignificant as a slight deficiency to something as drastic as total depravity. Western Christian tradition regards it as the general condition of sinfulness (lack of holiness) into which human beings are born, distinct from any actual sins that a person may or may not commit later. Eastern Christian Tradition too identifies original sin as physical and spiritual death, the spiritual death being the loss of "the grace of God, which quickened (the soul) with the higher and spiritual life"[1] Others see original sin also as the cause of actual sins: "a bad tree bears bad fruit" (Matthew 7:17, NIV), although, in this view, original and actual sin may be difficult to distinguish
Original sin
St. Anselm and even to the traditions of the early Church, as we see by the declaration of the Second Council of Orange (A.D. 529): one man has transmitted to the whole human race not only the death of the body, which is the punishment of sin, but even sin itself, which is the death of the soul [Denz., n. 175 (145)]. As death is the privation of the principle of life, the death of the soul is the privation of sanctifying grace which according to all theologians is the principle of supernatural life. Therefore, if original sin is "the death of the soul", it is the privation of sanctifying grace.
The Council of Trent, although it did not make this solution obligatory by a definition, regarded it with favour and authorized its use (cf. Pallavicini, "Istoria del Concilio di Trento", vii-ix). Original sin is described not only as the death of the soul (Sess. V, can. ii), but as a "privation of justice that each child contracts at its conception" (Sess. VI, cap. iii). But the Council calls "justice" what we call sanctifying grace (Sess. VI), and as each child should have had personally his own justice so now after the fall he suffers his own privation of justice.
We may add an argument based on the principle of St. Augustine already cited, "the deliberate sin of the first man is the cause of original sin". This principle is developed by St. Anselm: "the sin of Adam was one thing but the sin of children at their birth is quite another, the former was the cause, the latter is the effect" (De conceptu virginali, xxvi).
Original Sin
I don't know what you think I am confused about, we all sinned in Adam so we all die in Adam.