Adam and Eve began the first family after the fall from the Garden of Eden. They had two sons that pursued two very different vocations: one a farmer, the other a shepherd. There is much speculation as to why one offering was accepted above the other. The primary thought offered by scholars was that Abel’s motives were more pure and that he offered only the best as an offering to the Lord, whereas Cain simply offered “an offering.” This was an obvious mismatch in motive and quality of the offerings given to God.
The lack of acceptance by God of Cain’s offering made him especially angry and jealous of his brother Abel. He “rose up” against Abel his brother. The language here seems to signify an act of rage. Maybe Abel said something negative, maybe he simply praised God for accepting his offering, or maybe he said nothing at all. Whatever triggered Cain’s rage, he murdered his brother in cold blood. God asked Cain about Abel’s whereabouts, and Cain denied knowledge and uttered the infamous statement, “Am I my brother’s keeper?”
Cain was banished from the family and area, and complained that God was punishing him more harshly than he could handle. He felt he would instantly be killed because of his sin. So God marked him and proclaimed vengeance upon anyone who would kill him.
So what is the lesson here? Check your motives for anything you do. Keep a level head, no matter what disappointment, disgust, or embarrassment you may experience. And if you commit the crime, prepare to do the time. All the while, understand that God will grant a measure of grace, even as you suffer the consequences of your actions!