(1 John 2:16 KJV) For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
We see in the Genesis account, Adam and Eve both sinned. The serpent deceived Eve by putting a thought into her mind.
(Gen 3:1 KJV) Now the serpent was more subtle than any beast of the field which the LORD God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?
(Gen 3:2 KJV) And the woman said unto the serpent, We may eat of the fruit of the trees of the garden:
(Gen 3:3 KJV) But of the fruit of the tree which is in the midst of the garden, God hath said, Ye shall not eat of it, neither shall ye touch it, lest ye die.
(Gen 3:4 KJV) And the serpent said unto the woman, Ye shall not surely die:
(Gen 3:5 KJV) For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil.
The lust of the eye - seeing the fruit that was forbidden and desiring of it. The pride of life, desiring to make one wise (becoming like God, knowing Good and Evil. The lust of the flesh - eating from the fruit that was forbidden.
In the mind sin was conceived. For Adam and Eve knew they were not to eat the fruit from the tree in the middle of the garden. In the lust of the eye - seeing and desiring after the fruit. For they knew if they ate they would be like Gods (Pride), knowing good and evil. Eating of the fruit - the physical act which lead to disobedience and believing the word of the serpent over the word [command] of God (Lust of the flesh).
(Gen 3:6 KJV) 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.
(Rom 5:14 KJV) Nevertheless 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.
Similitude G3667. homoioma, hom-oy'-o-mah; from G3666; a form; abstr. resemblance:--made like to, likeness, shape, similitude.
Man's sin is a similitude of Adam's transgressions. Adam being the first man, who is a figure of him that was to come (Christ Jesus - the second Adam - the Redeemer). The first man is of the earth, the second man is the Lord from Heaven.
(1 Cor 15:47 KJV) The first man is of the earth, earthy: the second man is the Lord from heaven.
(1 Cor 15:48 KJV) As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly.
(1 Cor 15:49 KJV) And as we have borne the image of the earthy, we shall also bear the image of the heavenly.
(Gal 5:16 KJV) This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh.
(Gal 5:17 KJV) For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would.
(Gal 5:18 KJV) But if ye be led of the Spirit, ye are not under the law.
(Gal 5:19 KJV) Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness,
(Gal 5:20 KJV) Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies,
(Gal 5:21 KJV) Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God.
(Gal 5:22 KJV) But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
(Gal 5:23 KJV) Meekness, temperance: against such there is no law.
(Gal 5:24 KJV) And they that are Christ's have crucified the flesh with the affections and lusts.
(Gal 5:25 KJV) If we live in the Spirit, let us also walk in the Spirit.
(Eph 2:3 KJV) Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
(Eph 2:4 KJV) But God, who is rich in mercy, for his great love wherewith he loved us,
(Eph 2:5 KJV) Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved)
(Gal 6:8 KJV) For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.