SIN is mentioned 447/447 times in the KJV Bible

First question:

WHO IS SIN ?
The first mention of the word SIN is in Genesis 4:7 KJV
We are to walk circumspectly through the scriptures and so it is that I begin with verse 5.
But unto Cain and to his offering he (God) had no respect. And Cain was very wroth, and his countenance fell.
6. And the Lord said unto Cain, WHY art thou wroth? and WHY is thy countenance fallen?
7) If thou doest well, shalt thou not be accepted? and if thou doest NOT well,
SIN lieth at the door. And unto thee shall be HIS desire, and thou shalt rule over HIM.
God answers both questions:
1. If thou doest well, shalt thou not be accepted? and thou shalt rule over HIM.
 2.If thou doest not well, SIN lieth at the door. And unto thee shall be HIS desire.

Here we see that SIN is the Devil, a creation of God. A son of God that covered the throne of God. Ezekiel 28:14
Thou art the anointed cherub that covereth; and "I" have set thee so(:) thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.
SIN is an intity, the NAME of an individual, a personage, an angel of God, who was in the mountain of God (Heaven) and walked up and down in the midst of the heavenly angels,before [iniquity] was found in him.
Ezekiel 28:15 KJV
Thou wast PERFECT [in thy ways] from the day that thou wast created, TILL [iniquity] was found in thee.

INIQUITY means Wickedness.

Genesis 6:5 Is the FIRST mention of the word WICKEDNESS, and it relates to the state of mankind before the flood. A witness to the WAYS of SIN/ the Devil as stated by God in Ezekiel 28:15
Genesis 6:5 KJV
AND GOD SAW that the WICKEDNESS( SIN that lieth at the door) of man was [great] in the earth, and that EVERY [IMAGINATION] OF THE THOUGHTS OF HIS HEART WAS [ONLY] EVIL CONTINUALLY.

There is only ONE verse in the Bible where "SIN" is called "the son of wickedness" by God.
Psalms 89:22 KJV
Beginning with verse (20)
I' have found David my servant; with my' holy oil have I' anointed him (:)
21) With whom my' hand shall be established(:) mine arm' also shall strengthen him.
(22) THE ENEMY SHALL NOT EXACT UPON HIM; NOR "THE SON OF WICKEDNESS" AFFLICT HIM.

In the vision of Zechariah 5:5-11 KJV we read in verse (8) the angel that spake with Zechariah said, "this" in the ephah is " WICKEDNESS (.) " period.
And he (the angel) cast [IT] into the ephah; (  this [ephah] is a false balance =ing an Abomination unto God)
SIN/WICKEDNESS is in the form of a S/he, the [man of SIN,] so called by Paul in:
2 Thessalonians 2:3 KJV.
" Man of Sin " mentioned ONLY 1/1 times in the whole Bible.
"The Son of Perdition. 
" Son of Perdition " mentioned only 2/2 times in the whole Bible.
1. John 17:12 KJV

Jesus speaking: " While I' was with them in the world, I' kept them in thy name(:) those that thou gavest me I' have kept, and NONE of them is lost, BUT THE SON OF PERDITION; THAT THE SCRIPTURE MIGHT BE FULFILLED.
2. 2 Thessalonians 2:3 KJV
Paul speaking:  " Let No Man deceive you by ANY means (:) for [that day] shall NOT come, EXCEPT there come a falling away first, AND  that " man of SIN " BE REVEALED, " the SON OF PERDITION(;)

Literally the Devil/SIN in the flesh. An abomination in fleshly form, and in the form of spiritual wickedness/SIN/DEVIL.
There is only ONE mention in the whole Bible of the words " Satan entered into him ", [it] is found in
John 13:27 KJV
And after the sop "Satan entered into him" (.) period
Then said Jesus unto him, That thou doest, do quickly(.) period

Our Lord Jesus called Judas "the son of perdition".

Paul in 2 Thessalonians 2:3 KJV

Second Question
WHAT IS SIN ?
Above we see Who it is, now lets look at What SIN is.
Again we go back to Genesis 4:7 KJV
God said: [IF] THOU DOEST WELL, SHALT THOU NOT BE ACCEPTED ? AND THOU SHALT RULE OVER HIM. (SIN )
Doing well in the sight of God is to Acknowledge Him.
Proverbs 3:6 KJV
In ALL "THY WAYS" [acknowledge HIM] and HE shall direct thy path(s).

SIN is NOT acknowledging God in ALL our ways.
SIN is the father of lies and ALL unrighteousness. The unrighteous do not acknowledge God. They follow SIN and acknowledge him.
God tells us  through his prophet Hosea 4:6 KJV
My people are destroyed for the lack of knowledge (:) BECAUSE thou hast [rejected] knowledge, I' will also reject thee, that thou shalt be no priest to me(:) seeing that thou hast forgotten the Law of thy God, I will also forget thy children.

SIN was ( past tense) perfect in HIS WAYS in the day that God created HIM.
Adam was perfect in HIS WAYS in the day that God created HIM. Adam ruled over SIN while he acknowledged God. [It] was the day that Adam STOPPED acknowledging God, that SIN entered the world.
Romans 5:19 KJV
For as by ONE MAN"S disobedience [many] were made Sinners, so by the obedience of One shall many be made righteous.
Jesus Christ being that One Man of obedience and by him are we who acknowledge HIM, made righteous. Again we DO WELL and are accepted [IF] we acknowledge Christ.

Third Question
When is SIN ?
Sin is NOW and present and in the world, even from [before] God the creator created the earth and all that is therein. Jesus Christ "the Word" created he HIM. For not any thing was made that was not made by him John 1:3 KJV
SIN will ALWAYS be in the world [TILL] the [end] of the 1000 year reign of Christ.
In the SEASON at the end of that 1000 years, SIN is loosed ONCE more from the bottomless pit, from which he was cast at the end of tribulation.
At the end of THAT SEASON, He is cast into the lake of fire for eternity.

Fourth Question
Where is SIN ?
SIN dwells in all unrighteousness upon the earth and beneath the earth.
SIN is before the throne of God and accuses us daily.
SIN dwells in darkness and in him is NO light.
SIN is in all spiritual wickedness (Ephesians 6)
Sin is in all who walk in darkness and do not know the light that is in Jesus Christ.
SIN is under our feet, [IF] we DO WELL and acknowledge God.
SIN is in MUSIC, Ezekiel 28:13 KJV
SIN is in all who hide secrets. For God  reveals secrets, and makes known to the king Nebuchadnezzar what shall be in the latter days. Daniel 2:28 & 2:47
Daniel 2:22 KJV
He (God) revealeth the deep and secret things(:) he knoweth what is in the darkness, and the light dwells with him.
SIN is in our daily lives to cause temptation, strife, and discord, that we do not DO WELL and acknowledge God in all that we think and do.
SIN is in Pride by which we as believers struggle with constantly.
SIN is in disobedience whether it be with our parents, our relationship with God, or how we deal with others in business or in our church. (IT) is in our works of charity, love, and compassion for one another, as far as WHY we do it.
SIN is in our churches and sits upon the mount of the congregations of the North. He is head of the apostasy that is to come " the falling away " in these last days.
SIN is in Television and movies promoting ungodliness.
SIN is in pornography and perversion of the natural ways a man and woman should conduct themselves.
SIN is in the pulpit of the churches. Evil men who have crept in turning the Grace of God into lasciviousness, and denying the only Lord God and our Lord Jesus Christ. He is in the pastors who teach the lie of SIN spoken to Eve in the garden.
(ye shall be as gods)
SIN is in ALL forms of idolatry
SIN is in the worlds governments
SIN is head of 1/3rd of the angels that are fallen with him.
SIN is in ALL written word in all languages.
SIN is in the Bible. God tells us of SIN that we might know who he is.
SIN was in the life of our Lord Jesus Christ when he was tempted by him in the desert for 40 days and nights.
SIN is what our Lord bare for us in our stead, on that cross.
SIN is in The written word of God, other translations of it. When mans words are written along side God's words, SIN is there. Mans words are NOT pure.
SIN is in the perverting of the Word of God.
SIN is in our thoughts and minds, and ALL IMAGINATIONS
SIN is in man, through disobedience.
SIN is in five doves
SIN-NERS is who we are. All of us. There is none good, no; not one.

When I wake up each day I remind myself that I am a SINNER and it is ONLY through the Grace of God that I am redeemed by Faith in Jesus Christ.
In all these places and MORE, is SIN; but God through his love for mankind saw fit to become flesh and suffer for US, and by this unmatchable love can any of us overcome in the day of our fiery trial, which is to try us, and from the hour of temptation, which is to come.

Fifth Question
Why is SIN ?
SIN is... that God be glorified and lifted up, in the heavens and in the earth.
The LAW was given in order that SIN be made manifest in the sight of men. Before the Law, man knew [IT] not.
Before the Law, there was no [measure] for man as to what SIN encompassed.
The Law revealed SIN and showed man that it was IMPOSSIBLE in his present state, to please God. NO works of man can please God because of pride.
The Old Testament men were [accepted] by God, because they BELIEVED God, and that belief was counted unto them as righteousness.
These men and women who believed God, still Sinned. Their examples are written all through scripture. Noah the patriarch FOUND Grace in the sight of the Lord because he believed God. His belief caused him to be [accepted] by Doing Well through obedience. Genesis 4:7 KJV
God bestowed great patience before the Law, and with us during the earthly walk of Christ,(he knew our members before the foundations of the world, the Father gave us the believer to him) and WE again in our patience possess we our souls,(Luke 21:19) and are [accepted] by Doing Well, according to the gospel of Jesus Christ.
BELIEVE upon the Lord Jesus Christ and we shall be saved, EVEN to them that believe on his name.
It is good to do good works, and to proclaim the gospel of Christ, and live a godly life before men, but SIN always is laying in wait at the door, with pride and temptations that rob us of our reward. ( which is Christ himself)
It is through repentance, humility, and confession of our SIN that cleanses us of all unrighteousness, and causes the works that we do to be accepted by God.
This is WHY SIN is. SIN is a tool whereby God uses to bring us back to a [right] mindset and acknowledgement of him. In THIS is God glorified and lifted up.
Jesus said; [IF] I' be lifted up, I' WILL draw ALL men unto me.

May we in all our WAYS acknowledge God that we DO WELL and are accepted, and in doing so, we shall rule over HIM. (SIN) Genesis 4:7

God has declared the End from the Beginning. His counsel shall stand, and He will do all His pleasure.
It pleases God to use SIN to glorify himself in heaven and in the earth.

God Bless you all
KML