We know it is symbolic because certainly God does not need to ask Cain what happened to Abel. "The LORD" means Supreme Being, controller of everything. This means He knows everything. He doesn't have to ask Cain or anyone else where someone is.
And no one would be addressing the Supreme Being with such disrespect and sarcasm, as Cain says, "Am I my brother's keeper?"
But there is a symbolic meaning to Cain's disrespect and sarcasm.
Using symbolism to describe some of the complexities of spiritual reality is used throughout the teachings of the Bible, including Jesus, who used symbolic parables like the parable of the wedding banquet, the vineyard, and many others. While these are symbolic, they are still true. They are describing factual realities using symbolic characters.
While the conversation itself is symbolic, the exchange that takes place between God and Cain does actually occur - translated into events - between the Supreme Being and each of us who have fallen to the depths of the physical world.
In other words, the story of Cain and Abel is communicating what has taken place for each of us as we progressively fell from the spiritual realm.
The first phase of our fall came after we decided we wanted to be "like God" (Gen. 3:4) and we ate "the forbidden fruit" of self-centeredness and envy. We then were "cast out" (Gen. 3:23) of Eden (the spiritual realm), and we took on "garments of skin" (Gen. 3:21) - which are these temporary physical bodies.
Just after our fall to the physical world, we were still in a higher state of consciousness (relative to our current state). In this state, we still related to and recognized the Supreme Being, illustrated by Cain and Abel's making offerings to God.
But our envy and self-centeredness began to take further hold of us, as we became envious of each other. This is symbolized by Cain becoming envious of Abel (Gen. 4:5). His envy led to anger and violence, and Cain kills his brother.
Abel's death symbolizes how self-centeredness took hold within each of us to the extent that we were willing to kill others to achieve our goals. God explained the process earlier, as he told Cain, "But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it." Obviously, Cain, like each of us, does not master it.
This illustrates how each of us have continued to fall into the depths of mutual envy, lust, greed and violence as our self-centeredness ("sin") has continued to grip our consciousness ("have you").
This envy and greed also color our declining relationship with the Supreme Being during this progressive fall, as we began to look to God with disdain - symbolized by Cain's disrespectful and sarcastic response to God's question.
As a result of this progression of self-centeredness, hostility and violence, God then tells Cain that he will lose the ability to grow crops, and that he "will be a restless wanderer on the earth." What does this mean?
This consequence Cain must deal with symbolizes the law of consequences existing within the physical world. We must each suffer the consequences of our actions, whether good or bad.
It also illustrates how we continued our fall into the physical realm through the different species. Being "a restless wanderer on the earth" symbolizes our wanderings from one physical body to the next, and even one species to the next - as we have descended into the depths of hell in a progression of one physical body after another.
The design of the Supreme Being is that whatever self-centered action taken in the physical world has a reaction that is perfectly reflected back to us, either in this life or a future physical lifetime. This includes things that we do that might help others - which effect us positively in the future. The balance between the two, combined with the state of our consciousness (desires), determines our future fate.
This provides for what we might call consequence learning.
The Supreme Being's design utilizes the best way to learn. Child psychology research has even illustrated that 'consequence learning' is the best way for a child to be trained. This is because we learn best by experiencing the consequences of our actions.
The Supreme Being's consequential learning system programmed into the physical world has certain definitions. It only impacts us to the degree of our awareness and the awareness of those we affect. Thus humans will receive clear consequences, because we humans have the awareness of how our actions can help or hurt others. Animals, fish, insects, plants and microorganisms are generally in survival mode. They do not suffer consequences because they are not aware of how their actions affect others.
If we hurt another without realization then there is less consequence. But to the degree we know our actions will hurt another, there will be a corresponding reaction. This is also reflected in our justice system, which punishes crimes of premeditation (such as "murder") more than accidental crimes ("manslaughter").
Some have called this "as you sow, so shall you reap."
Others have called this consequence system the "law of karma."
Still others have referred to it as "going to hell."
In fact, every scriptural reference to "going to hell" includes the concept of consequence. It is not as if a person "goes to hell" by accident. We "go to hell" because of our activities. "Going to hell" is 'consequence learning.'
But where is hell? Many imagine hell as an underground fiery cave with people chained to walls while a horned red devil beats them.
Sorry, but we are in hell right now. Hell is a place of suffering, with each of our bodies suffering precisely to the extent of the consequences of our prior actions.
The creatures around us - the animals, fish, insects and even microorganisms - are all living in hell. These bodies present relative degrees of hell to the person inhabiting that body.
Humans also experience hell. This is why one person can be living in Somalia, undergoing torture and rape at the hands of evil mercenaries (devils) while another person is living in Hawaii in a luxurious house on the beach. It is also why some children are born into wealth and inheritance while others are born into abject poverty.
This is precisely why many people think that God is not fair. They put forth an important question:
"If God exists, why does He allow so much suffering?"
The reason most of the organized sectarian institutions today cannot answer this is because their professional teachers do not know the answer. This of course leads to intelligent people straying from their faith in God.
There is a clear answer to this question, however.
First, we are not these physical bodies. Our bodies are temporary vehicles, which we operate for a few decades. They are like automobiles that we get in and drive for a while and then get out. This means those things that happen to our physical body do not actually happen to each of us. It is like a car getting in a fender-bender. The car may be totaled, but we can get out and walk away. (Not the best analogy because people also get hurt in car accidents.)
Better yet, we might compare this world and these bodies to playing a video game. We can sit down at the computer, select an icon, and start playing a video game. Our icon can get shot at, run over or beat up by the virtual reality programming. Our icon might even be killed. No matter what happens to our icon, we can still turn off the computer and walk away, no matter what happened inside the video game.
Just as a person might start identifying with their video game icon, we also begin to identify ourselves with these temporary physical bodies. As we do this, we get immersed in the programming inherent in the physical world, just as a person gets immersed in a video game.
As we get immersed in the physical world, we forget our real identities as spiritual, where we came from, and the fact that our natural position is with the Supreme Being in the spiritual realm. This is, of course, by design, because we wanted to get away from the Supreme Being - which is why Adam, symbolizing each of us, ate the "forbidden fruit" in the first place.
This is also why we spend so much of our lives looking for that perfect mate who will love us, care for us and fulfill us. This is also why we all share this feeling that we belong in a world that is peaceful, where everyone loves each other. Innately it is the Supreme Being we are looking for, and it is the spiritual realm we are trying to return to.
In other words, we do not physically suffer - only our virtual, temporary physical bodies suffer. They suffer by design. Our bodies suffer - each uniquely, depending upon our past actions - during birth, when teething, when hungry, when sick, when hurt, when cold, and when hot. They also suffer from diseases, aging, and eventually death.
But this suffering is happening to the physical body, not us. We are each spiritual persons 'driving' a temporary physical body.
Second, this system of 'consequence learning' is designed to teach us, in order to raise our consciousness. Should we ignore the opportunity to raise our consciousness, we are plunged into species of ignorance - precisely to the extent we want to ignore reality. But if we embrace the lessons physical life teaches us, and we seek the wisdom from them, then our consciousness becomes raised, as we learn more and more about who we are and what our purpose for existence is.
And finally, most importantly, the Supreme Being has set up an escape valve for us. We might compare this to the old cartoon, "Tooter the Turtle" - about the turtle who asks the wizard to get sent into different situations. Then, when the turtle gets into a tough situation, he shouts "Mr. Wizard, Mr. Wizard, help me!" and the wizard then pulls the turtle out of the situation and back home. The Supreme Being has a similar escape valve set up for each of us. At any time, at any place, regardless of our situation, we can call the Supreme Being and He will pull us out of this 'consequence system' and bring us back home to Him. This is His promise - His covenant - with each of us.
Plus He is always calling us back home through His representatives and through scripture.
We are like children who have run away from home. But in this case, our parent happens to control everything. So He designed a place - this physical world - where we could feel that we are really away from home. This place He designed gives us independence and the facilities to act out our desires.
He also programmed the physical world with facilities that teach us. We might compare this to a Dad who builds a tree-house for his son, so his son could get away from the house and pretend he has his own house. But like the good Dad who built the tree-house, the Supreme Being is always there for us, lovingly waiting for us when we want to return to Him.
But we must remember that we also have to be ready to return to Him. Most of us are not ready, because we are immersed in the depths of self-centered consciousness. This requires a purification process.
For anyone who sincerely asks the Supreme Being to return home to Him, He begins to guide us and prepare us for our return home. This is a personal training process unlike the consequential learning system, because it is custom-designed for each of us, to help us re-establish our lost loving relationship with Him.
And this is the purpose for all the spiritual teachers that God has sent through the ages. They have been sent specifically to help train those who have requested from God to help them return home to Him.
This is also why the "first and greatest commandment" as taught by Jesus and Moses, focuses on returning to our loving relationship with God:
“‘Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment." (Matt. 22:37-38)