There is more involved in Adam and Eve’s choice to eat from the “tree of knowledge of good and evil” as being a sin. It is not like the act of a child stealing a piece of fruit from a fruit stand. This was a rebellion against their Creator, Jehovah God. What escapes most humans is that they were created, and there is a Creator. The desire for absolute independence runs contrary to this and is hard for him to accept. Jehovah God had every right in setting a tree that would establish the point of his sovereignty (right to rule). Adam and Eve were created and did not have absolute independence and freedom; it was relative to their environment as created persons, which is a lesson that they needed to understand through more than mere words.
If perfect humankind were to do as Jehovah had requested, multiply and fill the earth, it would have resulted in a paradise wide planet, filled with perfect human creation. If there was to be universal peace, man needed to appreciate that he had been created and that he was designed to walk with God, not walk on his own. This would have been established if the first two, especially Adam, were to refrain from eating from the “tree of knowledge of good and evil.” Adam was to become the father to all of perfect humankind, and he needed to be loyal to his Creator, proving his obedience, by this one small act of refraining from eating from the forbidden tree.
Luke 16:10 Updated American Standard Version (UASV)
10 “The one who is faithful in the least thing is also faithful in much, and the one who is unrighteous in what is least is also unrighteous in much.
Both Adam and Eve were able to choose not to eat from the tree. In fact, they were designed in such a way that to do bad would be going against their natural inclinations. Of course, they knew the difference between good and bad. It was bad to eat from the forbidden tree, and it was good not to eat from it. Therefore, it was not a matter of their being ignorant of good and bad, as though God were trying to keep such knowledge from them. Thus, the tree or its fruit had no intrinsic substance, which would wake them up to the idea of what is good and what is bad. The good and bad was the ability to choose what is good and bad. The right and wrong of life belonged under the umbrella of the sovereignty of their Creator, not man. If man lived under the standard of right and wrong of his Creator, all would remain perfect.
A footnote on Genesis 2:17, in The Jerusalem Bible represents well what the tree stood for (1966):
This knowledge is a privilege which God reserves to himself and which man, by sinning, is to lay hands on, 3:5, 22. Hence it does not mean omniscience, which fallen man does not possess; nor is it moral discrimination, for unfallen man already had it and God could not refuse it to a rational being. It is the power of deciding for himself what is good and what is evil and of acting accordingly, a claim to complete moral independence by which man refuses to recognize his status as a created being. The first sin was an attack on God’s sovereignty, a sin of pride.