What is SIN?

[Esaias]

Originally Posted by KeptByTheWord

According to 1 John sin is unrighteousness, and transgression of the law.

1 John 3:4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.

Apparently John is the only writer in scripture that actually says "sin is" and defines what sin is. Correct me if I'm wrong? There are a lot of scriptures about sin, but is 1 John is the only place where sin is actually defined as "sin is"?

I believe that is correct.

Then John says:

1 John 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.

... "he that committeth sin is of the devil..."

In light of that passage, how exactly do we define WHAT is sin?

Sin is transgression of the law. Therefore whatever is a transgression of the law of God is sin. Dishonouring your parents is sin. Stealing is sin. Adultery is sin. Why? Because those things are violations of the law of God (transgressions).

The word sin however is also used to describe not merely the action which is forbidden, but (in the case of idolatry) the object which is sinfully (ie unlawfully) worshipped, or the place where such unlarful worship occurs. For example:

Hos_10:8 The high places also of Aven, the sin of Israel, shall be destroyed: the thorn and the thistle shall come up on their altars; and they shall say to the mountains, Cover us; and to the hills, Fall on us.

Amo_8:14 They that swear by the sin of Samaria, and say, Thy god, O Dan, liveth; and, The manner of Beersheba liveth; even they shall fall, and never rise up again.

But sin is defined Biblically as trangression of the law. The law defines and identifies sin:

Rom_7:7 What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet.

Jesus, of course, in the Sermon on the Mount, explained the spiritual application, and extent, of the law to not merely the outward physical action but to the intent of the heart as well, as when he identified unlawful lust as a form of adultery.

Mat 5:27 Ye have heard that it was said by them of old time, Thou shalt not commit adultery:
Mat 5:28 But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

As for 'the devil', the word devil means 'accuser'. It is a term that is taken from the concept of satan being one who accuses the people of God of their sins (see Job, etc). So the 'devil' is generally a NT term for 'satan', which is a Hebrew word for 'adversary' or 'enemy'. So then the 'devil' is the Adversary, that is, one who is opposed to God, his dominion (law), his grace, his divine Plan, etc. The devil 'sins from the beginning', that is, the enemy of God is in transgression, and is from the beginning. One who sins, ie one who transgresses God's law, is 'of the devil', much as Christ said to the Pharisees 'You are of your father the devil'. Being a 'child of' someone is a Hebrew figure of speech (a Hebraism) meaning one is partaking of the characteristic of someone, as if they were biologically descended from that someone. So the sinner is one who follows in the devil's footsteps, and bears the likeness of the devil - the enemy or opposer of God.

Thus, sin is the opposing of God and His ways, which are revealed in the law as explained and understood by the gospel.