Two brothers bring two offerings, and the LORD 4"had regard for Abel and his offering, but for Cain and his offering he had no regard." Genesis does not say why. It notes that Abel brought the firstborn of his flock and their fat portions, and that Cain brought 3"an offering of the fruit of the ground." Hebrews says Abel offered "by faith" (Hebrews 11:4), which points to the heart behind the gift.
Cain's face falls. Before Cain has done anything but sulk, God comes to him with a question and a warning: 7"If you do well, will you not be accepted? And if you do not do well, sin is crouching at the door." Sin is pictured as a predator waiting at the threshold, and the words used for it, desire and rule, are the same two words God used in Genesis 3:16 of the woman and her husband. Cain is handed what his parents never got, a warning spoken before the act, with the door to walking away still open.
8"Cain rose up against his brother Abel and killed him." Then God asks the question he once asked in the garden, now aimed differently, "Where is Abel your brother?" Adam at least admitted what he had done. Cain lies and sneers: 9"I do not know; am I my brother's keeper?" Within a single generation, sin has traveled further than it went in Eden.
The sentence on Cain escalates what fell on his father. Adam's ground was cursed because of him. Cain is cursed 11"from the ground," the soil that drank his brother's blood. Cain never says he is sorry. His only complaint is that the punishment is too heavy. And God answers that unrepentant complaint with protection anyway, placing a mark on Cain 15"lest any who found him should attack him." A murderer with no remorse still walks away guarded by the God whose ground received his brother's blood.
The chapter's last movement shows what grows from what. Cain's line builds a city and invents music and metalwork, and Lamech turns the family violence into a boast that his revenge will be 24"seventy-sevenfold." Sin does what it was warned it would do when left unruled. Then, quietly, Eve has another son, Seth, and by the time his own son is born, 26"people began to call upon the name of the LORD." After a murder and a killer's song, the chapter's last word is worship.
Abel's blood cried out from the ground. Hebrews says believers have come to "the sprinkled blood that speaks a better word" (Hebrews 12:24). Abel's blood asked for justice, and Christ's blood, shed unjustly by envious hands, asks for mercy on the people who shed it.
Ask what is crouching at your door this week, whether envy, resentment, or an old grievance. You have been told what to do with it, and the warning has come before the act.
Prayer
Father, we know how quickly the feeling of being overlooked can crouch at our own door. Thank you for the warning you give before the sin, and forgive us for the times we have not ruled over what was already asking to rule us. Thank you that Christ's blood speaks a better word than Abel's, mercy for people who deserved none. Let us be people who call on your name. In Jesus' name, amen.