Sin entered in the world when eve sinned!
1 tim 2:
13For Adam was first formed, then Eve.
14And Adam was not deceived, but the woman being deceived was in the transgression.
This scripture passage, establishes two things.#1, Federal Headship of the man, and # 2 that adam because of his headship was guilty of eves transgression, so much as so, it is said to be his rom 5:
14Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression, who is the figure of him that was to come.
You see, God called their name Adam gen 5:
1This is the book of the generations of Adam. In the day that God created man, in the likeness of God made he him; 2Male and female created he them; and blessed them, and called their name Adam, in the day when they were created.
So eves transgression was adams transgression..
Some will object to this, but its still true..
as soon as eve ate of the fruit, death pervaded their beings, Just as God said to adam gen 2:
16And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat: 17But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
You see, some erronously believe that adam had a choice as to wether or not he could have not eaten of the fruit his wife ate of and gave of him to eat.
Well the truth of the matter is, adam was already dead from the immediate effects of eves transgression, so he yielded himself as a servant of sin..
rom 6:
16Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
You see, adams unhestitant compliance to eves giving to him of the fruit to eat also, goes to prove that he was already dead to God, and alive to sin..sin had begun its rule over him and mankind at this time..