Thank you for the question on Adam and Eve, “If Adam and Eve had to eat from the tree of knowledge to know right from wrong, how could they know it was wrong to eat from the tree?”
Here are some thoughts on your question of Adam and Eve knowing Good and Evil:
A. Adam and Eve knew what was good. (Gen. 2:23–29),
When God made Eve and brought the woman to Adam, he didn’t think she was evil or bad. He saw her as someone very good for me. When they saw themselves being naked, they felt no shame or guilt. Adam was able to name the animals and the plants in the Garden of Eden. Adam saw Eve as a great creation of God for him.
Genesis 2 says this, “The man said, “This is now bone of my bones and flesh of my flesh; she shall be called ‘woman,’ for she was taken out of man.” 24 That is why a man leaves his father and mother and is united to his wife, and they become one flesh. 25 Adam and his wife were both naked, and they felt no shame. (NIV).
B. Adam and Eve did not have to eat from the Tree of Knowledge of Good and Evil.
Adam and Eve could eat any fruit or vegetable in the Garden of Eden. There was no prohibition except one. They were not to eat from the Tree of Knowledge of Good and Evil.
God gave Adam one prohibition. Genesis 2 says this, “The LORD God took the man and put him in the Garden of Eden to work it and take care of it. 16 And the LORD God commanded the man, “You are free to eat from any tree in the garden; 17 but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die” (NIV).
Adam and later Eve had the choice of not eating the prohibited fruit from the Garden. No one force Eve to it and no one force Adam to eat it. They could have refrain by listening to God or to ask God about it. They had a choice to make.
C. The fruit of Tree of Knowledge is described as being knowing good and evil. It is not knowing good from evil. There is a difference from knowing good and evil and knowing good from evil.
Genesis 1 says this, “17 but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die” (NIV).
Adam as well as Eve will have the capacity of knowing good and evil. At this point in the Garden, they didn’t know evil. Sin was no present. When they ate the forbidden fruit, the conscience and consciousness of good and evil were awaken within them. They knew that they had disobey God.
When Adam and Eve saw the birth of their sons and daughters, they saw that it was good to have children. When Cain killed Abel, they saw the evil of not having Abel with them anymore. They knew the good of birthing children and now they also know the evil of death. They will be able to contrast good and evil by the results.
The assumption that one knows good from evil is that one can choose good over evil. That was not the case as Cain knew good and evil, but he didn’t choose the good over evil. He succumbed to his evil desire.
The command of God to not eat the forbidden fruit should be sufficient to avoid the dire consequences of it. One does not have to experience the evil to know the terrible effects on oneself or others. It was wrong because God told Adam not to eat it.
One doesn’t have to take illicit drugs or be drunk and drive to know that it is evil or wrong. The warning sign should be sufficient to stay away from “the cliff”.
Summary: Adam and Eve knew it was wrong because God told them not to eat from the forbidden fruit. It was a command to avoid that action.
-Kingston