God now speaks a wise warning to Cain. Can will not heed it, but it is a warning for us as well. God asks Cain to adjust his understanding of what is good to God's understanding of goodness.
If Cain does well by God's standard, God will accept him. In other words, there is no reason for Cain to be angry about God's rejection.
What does Genesis mean?
The cure for that rejection is obedience: If Cain insists on setting his own standards for what is acceptable, sin "is crouching at the door. Sin desires to own us, and our refusal to let God set the standard for right and wrong in our lives is the fast track to sin. God acknowledges the reality of human nature. We are locked in a battle with sin's desire for us or our desire to sin. God tells Cain he is responsible to win that battle, to rule over his sin. The Hebrew terms used in this verse are exactly the same ones spoken to Eve in Genesis 3: These are from the root words tashuwqah , translated "desire," and mashal , translated "rule over.
Used by permission of Tyndale House Publishers, Inc. Notice how the offerings are described.
He was very angry and he showed his anger—towards God and Abel—with a downcast face! Why is your face downcast?
American Standard Version
Rather these questions were intended for self-examinations. God looks beyond the offering; he sees through the heart. In 1 John 3: Notice how God pictured sin. It also speaks of the readiness to attack. Wherever we go, sin is crouching at the door. If we give the devil or sin for that matter a foothold Ephesians 4: Cain was not just warned about sin.
He was also given a stern command to master sin. How are we going to master sin?
Compare Translations for Genesis 4:7
James tells us how—by submission to God. Just as the enemy is crouching, ready to attack, we must likewise keep watch and be alert to its presence, and resist him. Did Cain master sin?
Did he show self-control? Instead, Cain was dragged away by his evil desire James 1: He did not just express his anger and jealousy with a downcast face. Anger took its foothold with Cain.
He was so consumed with anger that he premeditated to murder Abel. Then, when the opportune time came, hiding his evil intention, Cain invited Abel to go out into the field, and once they were out in the field, Cain attacked and killed Abel, his brother.
The desire that mastered Cain had conceived, and had given birth to sin—murder! Then the moment of reckoning came. Anger and jealousy had made Cain indifferent towards his brother. Cain despised the responsibility given by God.