I’m just curious as to others definition or understanding of what sin is.
I like the Westminster Shorter Catechism.
Sin is any want of conformity unto, or transgression of, the law of God.
It's hard to improve on that as a concise definition of sin. As a longer definition, here is Easton's Bible Dictionary:
Sin
is "any want of conformity unto or transgression of the law of God" (1 John 3 1 Chr 3:4 Rom 4:15), in the inward state and habit of the soul, as well as in the outward conduct of the life, whether by omission or commission (Rom 6:12 -17; 7:524). It is "not a mere violation of the law of our constitution, nor of the system of things, but an offence against a personal lawgiver and moral governor who vindicates his law with penalties. The soul that sins is always conscious that his sin is (1) intrinsically vile and polluting, and (2) that it justly deserves punishment, and calls down the righteous wrath of God. Hence sin carries with it two inalienable characters, (1) ill-desert, guilt (reatus); and (2) pollution (macula).", Hodge's Outlines.
The moral character of a man's actions is determined by the moral state of his heart. The disposition to sin, or the habit of the soul that leads to the sinful act, is itself also sin(Rom 6:12 -17; Gal 5:17; James 1:14, 15).
The origin of sin is a mystery, and must for ever remain such to us. It is plain that for some reason God has permitted sin to enter this world, and that is all we know. His permitting it, however, in no way makes God the author of sin.
Adam's sin (Gen 3:1 6) consisted in his yielding to the assaults of temptation and eating the forbidden fruit. It involved in it, (1) the sin of unbelief, virtually making God a liar; and (2) the guilt of disobedience to a positive command. By this sin he became an apostate from God, a rebel in arms against his Creator. He lost the favour of God and communion with him; his whole nature became depraved, and he incurred the penalty involved in the covenant of works.
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; Rom 6:12 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; Rom 3:10. 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 Eph 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 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).
Various kinds of sin are mentioned, (1.) "Presumptuous sins," or as literally rendered, "sins with an uplifted hand", i.e., defiant acts of sin, in contrast with "errors" or "inadvertencies" (Ps 19:13). (2.) "Secret", i.e., hidden sins 19:12); sins which escape the notice of the soul. (3.) "Sin against the Holy Ghost" (q.v.), or a "sin unto death" (Matt 12:31, 32; 1 John 5 Matt 5:16), which amounts to a wilful rejection of grace.
(EBD)
