Generally I prefer the archaic complexities of the King James version but for clarity and simplification, I have used the New Living Translation, Genesis 4:9:
... the LORD asked Cain, “Where is your brother? Where is Abel?”
“I don’t know,” Cain responded. “Am I my brother’s guardian?”
As it transpires earlier in Genesis 4, Cain and Abel, born of Eve as sired by Adam, have chosen different career paths, Genesis 4:2-7:
When they grew up, Abel became a shepherd, while Cain cultivated the ground.
When it was time for the harvest, Cain presented some of his crops as a gift to the LORD.
Abel also brought a gift—the best of the firstborn lambs from his flock. The LORD
accepted Abel and his gift,
but he did not accept Cain and his gift. This made Cain very angry, and he looked dejected.
“Why are you so angry?” the LORD asked Cain. “Why do you look so dejected?
You will be accepted if you do what is right. But if you refuse to do what is right, then watch out! Sin is crouching at the door, eager to control you. But you must subdue it and be its master.”
Ponderances about the nature of God below:
Why was not Cain's offering acceptable?
Did Cain make the offering with the wrong attitude?
Is God a blood-thirsty carnivore who delights in fresh blood spilling over the Altar from the still beating heart of an innocent lamb?
Was God making a cultural observation on the transition of humanity from a nomadic, herding tribe to an established, land-owning society of agriculturists?
Was God testing the temperament of Cain, trying to get his Irish up?
At this point, also, I must deviate from NLT to the more concise language of KJV:
Am I my brother's keeper?
which I prefer to "Am I my brother's guardian?"
Is God taking on the role of Satan and tempting Cain to act out his baser instincts by snubbing him and tripping him into anger?
Or, is God making a more societal-oriented statement about owning property and creating a body of law which is more concerned with protecting property rights than human rights?
And, what about Cain's Ayn Randian question:
Am I my brother's keeper?
There it is: my
fair and balanced reporting on the Nature of God.
You decide.