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I hope that you don’t mind, I have included ‘transgression’ as well (at no extra charge).
In the Old Testament:
Exodus 34:7 Keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear the guilty...
Using Strong’s Concordance:
Iniquity <05771> ‘avon’ (from 05753 ‘avah’ – bend, twist, distort.)
Translated in the King James Version - iniquity 220 times, punishment 5 times, fault 2 times, Iniquities + 01697 1 time, mischief 1 time, sin 1 time.
1) perversity, depravity, iniquity, guilt or punishment of iniquity
1b) guilt of iniquity, guilt (as great), guilt (of condition)
1c) consequence of or punishment for iniquity
Iniquity (‘avon’), refers to wilful, knowing transgression of God's law where one's desires get the upper hand;
Transgression <06588> ‘pesha‘ (from 06586 ‘pasha’ – rebel, revolt.)
Translated in the King James Version - transgression 84 times, trespass 5 times, sin 3 times, rebellion 1 time.
1) transgression, rebellion
1a1) transgression (against individuals)
1a2) transgression (nation against nation)
1a3) transgression (against God)
1a3a) in general
1a3b) as recognised by sinner
1a3c) as God deals with it
1a3d) as God forgives
1a4) guilt of transgression
1a5) punishment for transgression
1a6) offering for transgression
Transgression (‘Pesha’) refers to a wilful transgression done specifically to spite God.
Sin <02403> ‘chatta’ah’ (from 02398 ‘chata’ – to miss the mark.)
Translated in the King James Version - sin 182 times, sin offering 116 times, punishment 3 times, purification for sin 2 times, purifying 1 time, sinful 1 time, sinner 1 time.
1) sin, sinful
2) sin, sin offering
2b) condition of sin, guilt of sin
2c) punishment for sin
2e) purification from sins of ceremonial uncleanness
Sin (‘chatta’ah’) refers to ‘missing the mark’; disobeying God’s commandments; whether knowingly or unknowingly.
Some examples of usage of the words:
Exodus 34:9 And he said, If now I have found grace in thy sight, O Lord, let my Lord, I pray thee, go among us; for it is a stiffnecked people; and pardon our iniquity <05771> and our sin <02403>, and take us for thine inheritance.
Job 34:37 For he addeth rebellion <06588> unto his sin <02403>, he clappeth his hands among us, and multiplieth his words against God.
Psalm 32:1 – A psalm of David - Blessed is he whose transgression <06588> is forgiven, whose sin <02401> is covered. 2 Blessed is the man unto whom the LORD imputeth not iniquity <05771>, and in whose spirit there is no guile... 5 I acknowledged my sin <02403> unto thee, and mine iniquity <05771> have I not hid. I said, I will confess my transgressions <06588> unto the LORD; and thou forgavest the iniquity <05771> of my sin <02403>. Selah. 6 For this shall every one that is godly pray unto thee in a time when thou mayest be found: surely in the floods of great waters they shall not come nigh unto him.
In the New Testament:
Paul helpfully quotes Psalm 32
Romans 4:6 Even as David also describeth the blessedness of the man, unto whom God imputeth righteousness without works, 7 Saying, Blessed are they whose iniquities are forgiven, and whose sins are covered. 8 Blessed is the man to whom the Lord will not impute sin.
Using Strong’s Concordance:
Iniquities <458> ‘anomia’ (from <459> ‘anamos’ lawless)
Translated in the King James Version - iniquity 12 times, unrighteousness 1 time, transgress the law + 4160 1 time, transgression of the law 1 time.
1) the condition of without law
1a) because ignorant of it
1b) because of violating it
2) contempt and violation of law, iniquity, wickedness
Iniquity refers to lawlessness; not having, knowing or acknowledging the law.
Sin <266> ‘hamartia’ (from <264> ‘hamartano’ – to miss the mark).
Translated in the King James Version - sin 172 times, sinful 1 time, offense 1time.
1) equivalent to 264
1a) to be without a share in
1b) to miss the mark
1c) to err, be mistaken
1d) to miss or wander from the path of uprightness and honour, to do or go wrong
1e) to wander from the law of God, violate God’s law, sin
2) that which is done wrong, sin, an offence, a violation of the divine law in thought or in act
3) collectively, the complex or aggregate of sins committed either by a single person or by many
Sin (‘hamartia’) refers to ‘missing the mark’; disobeying God’s commandments; whether knowingly or unknowingly.
Hebrews 9:15 And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.
Using Strong’s Concordance:
Transgression <3847> parabasis (from 3845 parabaino – side-step)
Translated in the King James Version - transgression 6 times, breaking 1 time.
1) a going over
2) metaph. a disregarding, violating
2a) of the Mosaic law
2b) the breach of a definite, promulgated, ratified law
2c) to create transgressions, i.e. that sins might take on the character of transgressions, and thereby the consciousness of sin be intensified and the desire for redemption be aroused.
Transgression refers to the breaking of a commandment distinctly given.
In conclusion - All iniquity and transgression is sin and misses the mark, but not all sin is equal in gravity to iniquity and transgression. This was reflected in the Law of Moses; offerings could not be made for certain offences – the sentence of the Law for murder or adultery, for example, was death. The Law convicted all men of sin, for none (except Christ) could keep it perfectly.
The penalty for all and every sin is death.
Ezekiel 18:4 Behold, all souls are mine; as the soul of the father, so also the soul of the son is mine: the soul that sinneth <02398> ‘chata’, it shall die.
Romans 6:23 For the wages of sin <266> ‘hamartia’ is death;
We can only be saved from death if all our sins are forgiven. Forgiveness of sins has been made possible for us by the sinless life and sacrifice of Jesus Christ.
John 8:24 I said therefore unto you, that ye shall die in your sins: for if ye believe not that I am he, ye shall die in your sins.
Acts 13:38 Be it known unto you therefore, men and brethren, that through this man is preached unto you the forgiveness of sins:
Forgiveness of sins is conditional upon belief of and obedience to the gospel of Christ.
Mark 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature. 16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned (condemned).
Acts 2:37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do? 38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins... 41 Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls. 42 And they continued stedfastly in the apostles’ doctrine and fellowship, and in breaking of bread, and in prayers.
Salvation from death is by resurrection to eternal life when Christ returns.
1 Corinthians 15:20 But now is Christ risen from the dead, and become the firstfruits of them that slept. 21 For since by man came death, by man came also the resurrection of the dead. 22 For as in Adam all die, even so in Christ shall all be made alive. 23 But every man in his own order: Christ the firstfruits; afterward they that are Christ’s at his coming.
I hope you have found this helpful.
God bless you,