After answering this question above in a list of answers to the questions in the OP, another thread has given me reason to answer this question in another form, as a homiletic narrative discussing how I understand the first part of Genesis. But I started with a preface about what went before in order to address the reasons why God did what he did, and I put that here.
So13.8 billion years ago (according to our measure of time), God created a place, time, and rules of automation we humans call the laws of nature, which incidentally made no distinction between substance and action (both matter and motion are forms of energy). So His very action was sufficient to provide whatever substance was required. And the rules provided for sufficient complexity for self-organizing processes to appear everywhere. But only in some places, and we don’t know for sure how rare they are, were the conditions right for the self-organizing process in biochemistry to acquire the ability to learn, grow, and adapt to changes in the environment – such as we call life.
Genesis says that God formed Adam from the dust of the earth and breathed into him the breath of life. Now some might read this visually like a comic book, but what I read here is quite different: God formed our bodies from the stuff of the earth by the laws of its nature and then He spoke to us and brought our minds to life. What can I say? I am a scientist and that is how see the world, and thus it is only natural that this would be part of how I read the Bible also.
Now living things do not learn in a vacuum, so God could play the role of farmer to the plants and shepherd to the animals and finally when one arose capable of communication then God could be their teacher and parent. So He adopted Adam and Eve as His children. But as children grow, they cannot remain toddlers forever where you guard them from every danger. There comes a time when they must learn to be responsible for their own well being. Thus the parent makes this transition with a parental command something like, “do not play in the street, or you will die.”
In this case the parental command was about eating the fruit of one of two trees with names that frankly do not sound like biological species: the tree of life and the tree of the knowledge of good and evil. While some choose to take this parable literally so they will not be in too much danger of learning something profound, I am willing to take my “talent” and invest a little thought to see where it will take me. The tree of life is easier for there are other references in the Bible. In Proverbs 3:18 it means wisdom. In Proverbs 11:30 it is the reward for righteousness. In Proverbs 13:12, it is a desire fulfilled. In Proverbs 15:4 it is a gentle tongue. In Revelations 2:7, eating of it is equated with being in the paradise of God. In Rev 22:2 it is a tree with many fruits which provide for the healing of all the nations. Adam and Eve were not forbidden to eat of this tree, and yet they did not eat of it. Why? As an evangelical Christian I would tend to sum all these things given in these passages in these words: developing a personal relationship with God. But whatever words you use, clearly these are things which are not so easy to acquire as reaching up and plucking a fruit from a tree.
Is it any surprise that doing the wrong thing represented by the other tree was different in this way. Doesn’t always seem so much easier to stumble and fall? Unfortunately we do not have help on the meaning of the other tree in the rest of the Bible. But we can take a clue from the first tree, and suppose that it also refers to something quite different from a magical fruit in a fairy tale. Well how about the actual words, “the knowledge of good and evil.” They seem rather puzzling. Why would a knowledge of good and evil be a bad thing? Isn’t the the objective of all our preachers in all our churches to teach us precise the same thing – to give us a knowledge of good and evil? Well in the context of the story this knowledge about good and evil sound like the other one – the tree of life, wisdom and all that. But remember, the tree of life wasn’t so easy to partake of. This leads me to ask whether there is shortcut people might take which is not a such good thing. Suppose the other tree represents getting the authority to say what is good and evil without having to go through the trouble of actually gaining any wisdom on the matter? Is that a troublesome enough thing to explain evil in the world?
Well… what comes to my mind when I think of this question is the Roman emperor Nero, who was declared god over the known world and dictator on all that was to be accepted as good or evil in the empire. Yikes! That looks like BIG trouble to me indeed. But what about Adam and Eve? What in the world could they do which would be like Nero being appointed emperor of the world? See that is the one of the complaints I often hear about this story. Why is there this poison fruit sitting in the middle of this garden which God made for His children. Well not only is it not a poison fruit, but I would suggest it is a part of them, in which case, being in the garden is unavoidable. And like the road which parents typically warn their children about, it has a very important function. The parental commandment “not to play in the road” isn’t meant to be forever. Can you see where this logic is leading? What is something which is a part of them, and which they will need in the future, but will put them in a position of authority on good and evil without having to actually learn this wisdom? Well they can be parents can’t they and if they do, doesn’t that put them in a position of authority? But does this necessarily mean they have any real wisdom?
So after their mistake, what happens? God goes to Adam and asks for an accounting. God gave him the commandment so he is the responsible party. And what is Adam’s reply? “It was that woman you gave me!” Pass the blame – modus-operandi for all human kind ever since. Where is Adam’s love for God and Eve? Nowhere in sight. Hardly surprising that Eve follows the same pattern. And where does God lay the blame? On all three of them, though just like a parent the whole purpose of the punishment distributed is to address their errors. To Adam, God is basically saying, you are on your own, cause from now on there is nobody to blame but yourself for anything which goes wrong. To Eve the message seems to be about paying more attention to her husband and about taking the matter of having children a very seriously. And what about the snake, also known as the angel Lucifer. What was that all about? Well Adam and Even wanted to pass the blame, so God gave them a real adversary. Responsibility and power go hand in hand. If you pass the blame then you give someone power over you.
Does this sound like I am finding the snake blameless? You betcha. An angel, as a product of design, is nothing but a tool – a servant. I am sure he was just doing his job to provide challenges to living things so they could learn and grow. Like a computer it might do a passable imitation of free will, but mostly it is only in interactions with people that they become unpredictable. BUT, if Adam and Eve want an adversary and someone to blame then far better that they should have Lucifer in this role, because blaming God will only bring disaster. Thus I find it rather amusing that Lucifer is typically given many goat-like features, for he is essentially a scapegoat. However, do not make the mistake of thinking that any of this means I have one iota of sympathy for this creature. I do not. It may be a role to which he has been assigned, but this doesn’t change what he represents. He is the personification of evil, and for evil I have nothing but contempt. BUT I do not believe in him as I believe in God. I will credit that he exists. But I will not credit him with the slightest responsibility for anything.