Concerning the doctrine of original sin- it is taught in Scripture. J.I. Packer, a well-respected scholar and theologian, said:
“Scripture diagnoses sin as a universal deformity of human nature, found at every point in every person (1 Kings 8:46; Rom. 3:9-23; 7:18; 1 John 1:8-10). Both Testaments have names for it that display its ethical character as rebellion against God’s rule, missing the mark God set us to aim at, transgressing God’s law, disobeying God’s directives, offending God’s purity by defiling oneself, and incurring guilt before God the Judge. This moral deformity is dynamic: sin stands revealed as an energy of irrational, negative, and rebellious reaction to God’s call and command, a spirit of fighting God in order to play God. The root of sin is pride and enmity against God, the spirit seen in Adam’s first transgression; and sinful acts always have behind them thoughts, motives, and desires that one way or another express the willful opposition of the fallen heart to God’s claims on our lives.
Original sin, meaning sin derived from our origin, is not a biblical phrase (Augustine coined it), but it is one that brings into fruitful focus the reality of sin in our spiritual system. The assertion of original sin means not that sin belongs to human nature as God made it (God made mankind upright, Eccles. 7:29), nor that sin is involved in the processes of reproduction and birth (the uncleanness connected with menstruation, semen, and childbirth in Leviticus 12 and 15 was typical and ceremonial only, not moral and real), but that (a) sinfulness marks everyone from birth, and is there in the form of a motivationally twisted heart, prior to any actual sins; (b) this inner sinfulness is the root and source of all actual sins; (c) it derives to us in a real though mysterious way from Adam, our first representative before God. The assertion of original sin makes the point that we are not sinners because we sin, but rather we sin because we are sinners, born with a nature enslaved to sin.
David in Psalm 51 who said “…Behold, I was brought forth in iniquity, and in sin did my mother conceive me (vs. 5).” The idea is not that the act of conception was itself sinful, but (as the parallel first line shows) that each worshiper learns to trace his sinful tendencies to the very beginning of his existence—not only from birth but even from before that, to conception. The psalms are replete with statements about sin being inborn and internal. Sin is inborn in all of humanity.
Total depravity entails total inability, that is, the state of not having it in oneself to respond to God and his Word in a sincere and wholehearted way (John 6:44; Rom. 8:7-8). Paul calls this unresponsiveness of the fallen heart a state of death (Eph. 2:1, 5; Col. 2:13), and the Westminster Confession says: “Man by his fall into a state of sin, hath wholly lost all ability of will to any spiritual good accompanying salvation; so as a natural man, being altogether averse from that good, and dead in sin, is not able by his own strength to convert himself, or to prepare himself thereunto” (IX. 3).”