The serpent (satan) did certainly lie and the first humans were deceived. God gave humans dominion over the earth. Satan wanted to usurp this dominion and the allegiance of humanity from God to himself.The tree of good and evil represented wisdom and understanding from God's perspective. Wisdom concerning good and evil that only God the Creator possesses. The tree was a test for the first humans to see whether or not they would trust their God and Maker for wisdom or some other source. They chose to listen to the serpent and trust his words over God's. The ramifications of living under the dominion of satan have impacted the world and human life ever since.
So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world; he was cast to the earth, and his angels were cast out with him. Rev. 12:9
Jesus said to him, It is written again, You shall not tempt the Lord your God. Again, the devil took Him up on an exceedingly high mountain, and showed Him all the kingdoms of the world and their glory. And he said to Him, All these things I will give You if You will fall down and worship me.Then Jesus said to him, Away with you, Satan! For it is written, You shall worship the Lord your God, and Him only you shall serve. Matthew 4:7-10
But even if our gospel is veiled, it is veiled to those who are perishing, whose minds the god of this age has blinded, who do not believe, lest the light of the gospel of the glory of Christ, who is the image of God, should shine on them. 2 Cor. 4:3-4
Jesus came to bring freedom from the power of satan and deliver us from evil. (Matthew 4:6; Acts 26:14-18; Gal. 1:4)