Gen 3:1 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?
The serpent was satan or was indwelt by satan.
Satan was in the garden
Ezek 28:13 Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
Satan was created with beautiful precious stones covering him, similar to how New Jersualem will look, even with transparent gold. He was created with music, tabrets or tamberines, and pipes, flutes or organ sounds.
Ezek 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.
He covered the holy of holies in heaven.
Ezek 28:15 Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
He was created perfect, until iniquity was found in him. What was his sin? Pride, wanting to make himself as God. Angels are created to serve, not to rebel. There is no repentance for a rebelling angel.
Ezek 28:16 By the multitude of thy merchandise they have filled the midst of thee with violence, and thou hast sinned: therefore I will cast thee as profane out of the mountain of God: and I will destroy thee, O covering cherub, from the midst of the stones of fire.
Satan was full of self and God cast him out and will destroy him. He knows his time is short.
Ezek 28:17 Thine heart was lifted up because of thy beauty, thou hast corrupted thy wisdom by reason of thy brightness: I will cast thee to the ground, I will lay thee before kings, that they may behold thee.
He thought he was so special, full of pride, he was cast to the earth, we will see his end.
Ezek 28:18 Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by theiniquity of thy traffic; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to ashes upon the earth in the sight of all them that behold thee.
Ezek 28:19 All they that know thee among the people shall be astonished at thee: thou shalt be a terror, and never shalt thou be any more.
He will be no more, thrown into the lake of fire.
The serpent or dragon
Job 26:13 By his spirit he hath garnished the heavens; his hand hath formed the crooked serpent.
Isa 51:9 Awake, awake, put on strength, O arm of the LORD; awake, as in the ancient days, in the generations of old. Art thou not it that hath cut Rahab, and wounded the dragon?
Rev 12:7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
Rev 12:8 And prevailed not; neither was their place found any more in heaven.
Rev 12:9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Rev 20:2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years, Sin judged, the brass serpent on the cross.
John 3:14 And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up:
Brass is a type of judgment. Jesus judged the devil upon the cross.
Pride, I will be as God
Isa 14:12 How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
Isa 14:13 For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
Isa 14:14 I will ascend above the heights of the clouds; I will be like the most High.
Isa 14:15 Yet thou shalt be brought down to hell, to the sides of the pit.
Isa 14:16 They that see thee shall narrowly look upon thee, and consider thee, saying, Is this the man that made the earth to tremble, that did shake kingdoms;
Isa 14:17 That made the world as a wilderness, and destroyed the cities thereof; that opened not the house of his prisoners?
...Yea, hath God said, Ye shall not eat of every tree of the garden?
He planted doubt into Eves mind. To doubt God is to sin. Satan, the liar, seemed to have more authority than God. We must not follow any other spirit, that is not in accord with God's word.