Gen 3:6  And when the woman saw that the tree [was] good for food, and that it [was] pleasant to the eyes, and a tree to be desired to make [one] wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat.

Gen 3:7  And the eyes of them both were opened, and they knew that they [were] naked; and they sewed fig leaves together, and made themselves aprons.

 Sin is disobeying God.  God had told them not to eat of the tree and they disobeyed.  They only had one rule.  There was no excuse for their willfully disobeying God’s command. 

 Adam’s sin is what brought sin into the world

 Rom 5:12  Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:

 And we all have sin.  We inherited it from Adam.  Death is the result of sin.  All men die because all men have sin.  Are you going to die someday – then you have sin.

 Adam passed his sin to his descendants

 Gen 5:3  And Adam lived an hundred and thirty years, and begat [a son] in his own likeness, after his image; and called his name Seth:

 Adam was created without sin in the image of God, but notice, when Adam had children they were not created in God’s image.  They were created in Adam’s likeness, after Adam’s image, which was now a sinner.  Adam passed his sin nature to his children, and they passed it to their children and so on until it was passed to you.

 All men are born with sin

 Job 15:14  What [is] man, that he should be clean? and [he which is] born of a woman, that he should be righteous?

 Job 25:4  How then can man be justified with God? or how can he be clean [that is] born of a woman?

 Psa 51:5  Behold, I was shapen in iniquity; and in sin did my mother conceive me.

 The sin nature is not acquired later in life, it is not acquired the first time that you do something wrong.  The sin nature is not received at birth.  You get the sin nature when you are conceived.  At conception you are shapen in iniquity.

 Gal 3:22  But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.

 1Ki 8:46  If they sin against thee, (for [there is] no man that sinneth not,) and thou be angry with them, and deliver them to the enemy, so that they carry them away captives unto the land of the enemy, far or near;

 Ecc 7:20  For [there is] not a just man upon earth, that doeth good, and sinneth not.

 The above verses make is very clear that all men have sin and yes that would mean you.

 There is only one who does not have any sin

 2Co 5:21  For he hath made him [to be] sin for us, who knew no sin; that we might be made the righteousness of God in him.

 Heb 4:15  For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as [we are, yet] without sin.

 Heb 7:26  For such an high priest became us, [who is] holy, harmless, undefiled, separate from sinners, and made higher than the heavens;

 Jesus is the only one who did not have any sin of his own.  That is why He could die for our sins.  Jesus was the just dieing for the unjust.

 1Jo 3:5  And ye know that he was manifested to take away our sins; and in him is no sin.

 The reason that He came to the earth (was manifested) was to die for our sins on the cross.  He paid for our sins on the cross because we cannot pay for them ourselves.

 Isa 64:6  But we are all as an unclean [thing], and all our righteousnesses [are] as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.

 To God all your righteousnesses (all your good works to try to earn heaven) are filthy rags.  Think of it this way.  If you could work your way to heaven, then there would have been no reason for Jesus to have to die on the cross.