"And the serpent said unto the woman, Ye shall not surely die: for God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be AS, AS, AS God, knowing good AND, AND, AND evil." Genesis 3:4-5 (emphasis added).
Or, put another way, Satan's core lie here was about God's nature -- that God experientially knew good AND evil, that God in fact authored good AND evil, that God ultimately WAS good and evil. So, the "knowledge of good and evil" is really the knowledge OF God AS the source of BOTH good AND evil.
And here is the poison. Once WE partake of THAT core lie--that God is internally dualistic, radically bipolar, ferociously fickle, violently volatile, and horribly inconsistent--then WE likewise become those things. The history of man has proved that proposition to be true. In short, we follow our image of God. Our destiny is determined by our view of God. If we believe God is BOTH good and evil, BOTH loving and wrathful, THEN so too will we be.
A. W. Tozer rightly believed that we tend "by a secret law of the soul" to gravitate toward and grow to resemble our mental image of God. Thus, Tozer was convinced that what comes to your mind when you think about God is the most important thing about you. High thoughts of God bring us into pure worship and a sanctified walk, while low thoughts of God defile our hearts and corrupt our walk.
The bottom line is that you become what you believe about God. Simply put, Satan's foundational lie to us all is is that God is "not" ONLY good, ONLY light, and ONLY love. He is ALSO evil, ALSO dark and ALSO wrath. And since Satan is the ACTUAL source of all the evil and dark dynamics mentioned above, then what Satan is really doing is inserting himself into our image of God. He is illegitimately joining himself to God's hip within our own understanding. And this is exactly what happened to the Old Testament saints. They had an undifferentiated view of God which caused them to wrongly attribute the destructive works of Satan to God. They erroneously believed Satan was God's "angry voice," His "left hand of wrath" in other words.
Oswald Chambers said that, "The origin of all sin is found in the mistrust of God's character." To remove Satan's lie from our image of God is to remove Satan's attributes from the divine nature-- to forever separate and sever Satan's nature from God's nature. We do this not just so we can behold God clearly, but so that we can be transformed into His likeness.
"But we all, with unveiled face beholding as in a mirror the glory of the Lord, are transformed into the same image from glory to glory, even as from the Lord the Spirit." 2 Corinthians 3:18.
"Beloved, now are we children of God, and it is not yet made manifest what we shall be. We know that, if he shall be manifested, we shall be like him; for WE SHALL SEE HIM EVEN AS HE IS." 1 John 3:2.
The core revelation needed to see PAST Satan's lie and INTO the real image of God is THIS -- God didn’t create evil, God doesn’t use evil, and God won’t allow evil. God is good. Only good. Always good. His only connection with evil is to disallow it through the power of the cross. In fact, God has already disarmed and disallowed every form of evil.
Why evil still occurs is due to man’s individual and corporate neglect of Jesus' "so great a salvation." This neglect invites Satan's eclipses to continue by falsely accusing God of evil. But, not so! Jesus Christ is God’s perfect cure for evil, a cure which overcomes evil one way and one way only - - with good. Jesus, as God in the flesh, came to reveal the true nature of God as good, love, light, truth and Spirit. Jesus is the tree of life. He is NOT internally dualistic.
No Old Testament saint saw the perfect goodness of God. Only Jesus accurately reflected, and still reflects, the true nature of God. Don't allow Satan to disguise this truth!
“No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him.” John 1:18.