In the Garden of Eden, God gave Adam a special command concerning one tree:
“But of the tree of the knowledge of good and evil, thou shalt not eat of it.” — Genesis 2:17
Many people ask:
Why was it called the tree of the knowledge of good and evil?
Why did God forbid Adam to eat from it?
Was there something evil inside the fruit itself?
Why would God place such a tree in the garden at all?
Francis Turretin answered these questions carefully and logically. Below is a simplified explanation of his teaching while keeping his theological depth.
The tree itself was not sinful, poisonous, or magical.
God created everything good.
“And God saw every thing that he had made, and, behold, it was very good.” — Genesis 1:31
The evil did not come from the fruit itself, but from Adam’s disobedience to God’s command.
Just as bread and wine in the Lord’s Supper are ordinary elements used for a holy purpose, this tree was an ordinary tree appointed for a special purpose by God.
The sin was not in touching fruit, but in rejecting God’s authority.
Turretin explains that the tree received its name from what would happen after Adam ate from it.
Before the fall, Adam already knew good in some measure. He knew God, holiness, righteousness, and obedience. But he did not know evil by experience.
After eating the fruit, Adam would know:
good — by losing it,
evil — by experiencing it personally.
So the tree became the occasion of experiential knowledge.
It was not a tree that magically gave wisdom. Rather, through disobedience Adam came to know evil tragically and painfully.
Like a man who learns the bitterness of disease only after becoming sick, Adam learned evil by falling into sin.
This agrees with Genesis 3:22:
“Behold, the man is become as one of us, to know good and evil.”
Not that man became divine, but that he now knew evil experimentally through guilt, misery, shame, fear, and corruption.
God gave this command for several important reasons.
God wished to prove and display Adam’s obedience.
Adam was created righteous, but his obedience needed to be exercised voluntarily.
Love and obedience are shown when a command must be obeyed.
Without a command, there could be no test of submission.
The command concerning the tree was simple, clear, and easy:
“Do not eat.”
This showed that Adam’s fall came not from weakness in the command, but from rebellion in the heart.
The forbidden tree reminded Adam that he was a creature under God’s authority.
Adam was given dominion over the earth, yet even in paradise there was one restriction.
This taught that man is never independent from God.
Even holy Adam had to live by God’s Word.
The tree stood as a visible sign that:
God alone determines good and evil,
God alone has supreme authority,
man must not seize autonomy for himself.
The serpent later tempted Eve precisely at this point:
“Ye shall be as gods.” — Genesis 3:5
The temptation was essentially this:
“Do not submit to God’s rule. Decide for yourself.”
This is still the essence of sin today.
Turretin taught that God entered into a covenant with Adam, often called the Covenant of Works.
In this covenant:
life was promised upon obedience,
death was threatened upon disobedience.
The tree functioned as a covenant sign and test.
“In the day that thou eatest thereof thou shalt surely die.” — Genesis 2:17
Adam represented the whole human race. When he sinned, humanity fell with him.
“By one man sin entered into the world, and death by sin.” — Romans 5:12
Thus the tree was not merely about food. It was about covenant faithfulness toward God.
Turretin carefully explains that God was not the author of sin.
Adam was created upright.
“God hath made man upright.” — Ecclesiastes 7:29
Adam had:
true righteousness,
genuine holiness,
freedom of will,
ability to obey.
But Adam was also mutable — capable of change.
Only God is incapable of falling.
God permitted the fall wisely and sovereignly, yet the blame belonged entirely to man.
The fall revealed:
God’s justice in punishing sin,
God’s mercy in salvation,
God’s grace through Jesus Christ the second Adam.
“For as in Adam all die, even so in Christ shall all be made alive.” — 1 Corinthians 15:22
Adam’s sin seemed small outwardly — merely eating fruit.
But inwardly it was enormous:
unbelief,
pride,
self-rule,
rejection of God’s authority.
This teaches us that no sin is small because every sin opposes the holy God.
The serpent suggested that God was withholding something beneficial.
Satan still tempts people this way:
“God’s commands are restrictive.”
“True freedom is doing what you want.”
But real freedom is found in obedience to God.
Adam failed the test in the garden.
Christ succeeded where Adam failed.
Adam brought death through disobedience. Christ brings life through obedience.
“For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous.” — Romans 5:19
The tree was called the tree of the knowledge of good and evil because through eating it Adam came to know evil by tragic experience and good by losing it.
God gave the command:
to test obedience,
to display His lordship,
to establish covenant responsibility,
and to teach man dependence upon God.
The tree itself was not evil. The evil was in disobeying God.
The entire event reveals the seriousness of sin, the justice of God, and the necessity of Christ as the Redeemer of fallen mankind.