4 Now Adam knew Eve his wife, and she conceived and bore Cain, saying, “I have gotten a man with the help of the Lord.” 2 And again, she bore his brother Abel.
It's sometimes said that Gen 3 doesn't really teach the Fall of man. Doesn't really teach original sin. That's a later reinterpretation of the text from church history.
i) To begin with, Bible teaching is often incremental. Even if Gen 3, all by itself, didn't teach original sin, it may record that turning-point in history. The full significance of that event will then become more evident as Bible history unfolds.
ii) Indeed, the story of Cain and Abel vividly illustrates the dire consequences of the Fall. The moral freefall is almost instantaneous.
Now Abel was a keeper of sheep, and Cain a worker of the ground.
Unlike the garden of Eden, where delicious food lay within arm's reach, life outside the garden forces people to have more than one source of subsistence. A mixed economy is a buffer in hard times.
3 In the course of time Cain brought to the Lord an offering of the fruit of the ground, 4 and Abel also brought of the firstborn of his flock and of their fat portions. And the Lord had regard for Abel and his offering, 5 but for Cain and his offering he had no regard. So Cain was very angry, and his face fell.
i) The narrator doesn't tell us why God accepted Abel's offering, but rejected Cain–leaving it up to the reader to draw his own conclusions. Some commentators try to explain the differential factor in objective differences between the type of offering. For instance, one scholar has proposed that Cain's offering was unacceptable because the ground was cursed. However, one problem with that explanation is that vegetative offerings are part of the Mosaic cultus. So there's nothing inherently unacceptable about vegetative offerings from a religious standpoint.
ii) I think God is using reverse psychology. By spurning Cain's offering, Cain's reaction exposes his underlying attitude, which is why God rejected his offering. Although Cain's reaction takes place after God spurns his offering, it unmasks a preexisting attitude. And that's why God snubbed him in the first place. What happens afterwards is the explanation for what happened before. In a sense, the effect precedes the cause, but that's because God reads his heart.
6 The Lord said to Cain, “Why are you angry, and why has your face fallen? 7 If you do well, will you not be accepted? And if you do not do well, sin is crouching at the door. Its desire is for you, but you must rule over it.”
Temptation is personified as a demon or predatory animal that waits outside to pounce the moment you open the door.
8 Cain spoke to Abel his brother. And when they were in the field, Cain rose up against his brother Abel and killed him.
i) Because Adam and Eve forfeited the tree of life, they were condemned to die of old age. Yet the first fatality isn't due to natural causes, but murder.
ii) Murder is one of the worst sins, but fratricide is an aggravated form of murder. Evil accelerates at a terrifying pace.
iii) For parents to outlive their kids is a great tragedy for parents. In a way, that's more punitive than their exile from Eden. Sin has unintended consequences. This is one reason we need to obey God. We can't foresee the chain-reaction which sin may trigger.
9 Then the Lord said to Cain, “Where is Abel your brother?” He said, “I do not know; am I my brother's keeper?” 10 And the Lord said, “What have you done? The voice of your brother's blood is crying to me from the ground. 11 And now you are cursed from the ground, which has opened its mouth to receive your brother's blood from your hand. 12 When you work the ground, it shall no longer yield to you its strength. You shall be a fugitive and a wanderer on the earth.”
This illustrates the homeless motif in Scripture. Our first parents are banished from Eden. Then Cain is banished from the human community. Social alienation is one consequence of sin. Loneliness. Emotional isolation.
13 Cain said to the Lord, “My punishment is greater than I can bear. 14 Behold, you have driven me today away from the ground, and from your face I shall be hidden. I shall be a fugitive and a wanderer on the earth, and whoever finds me will kill me.”
Cain is the first sociopath. He has no conscience. No remorse. No sense of guilt. No concern for others. Having murdered his own brother, he plays the victim, wallowing in self-pity. This vividly exemplifies the moral blindness of sin.
15 Then the Lord said to him, “Not so! If anyone kills Cain, vengeance shall be taken on him sevenfold.” And the Lord put a mark on Cain, lest any who found him should attack him.
Critics find this anachronistic. Where were all the humans who were going to avenge Abel's murder?
i) However, the text looks ahead to explosive population growth. Large, extended families. Keep in mind that the prediluvians had extraordinary lifespans, so a single breeding pair could lead to exponentially expanding families. Indeed, the narrator will clarify the proleptic reference in the genealogies that follow (e.g. Gen 4:17,25-26; 5:4).
In addition, until humans began dying of old age, Cain had no way of knowing how long humans had to live. He has no precedent, no sample group.
ii) We should also keep in mind that this is Cain speaking, and not the narrator. Cain's fears may be unjustified. He may be paranoid. He's not a stable individual–to say the least.
iii) But this also foreshadows the avenger of blood. If not in Cain's lifetime, certainly at a later date.
16 Then Cain went away from the presence of the Lord and settled in the land of Nod, east of Eden.17 Cain knew his wife, and she conceived and bore Enoch.
Unbelievers love to dust off the old chestnut: where did Cain get his wife? At this stage of human history, you had interbreeding.
Unlike parental incest, which is intrinsically wrong, sibling incest is not intrinsically wrong. Sibling incest is imprudent over the long-haul since interbreeding depletes the gene pool, leading to birth defects. But it's not inherently immoral.
When he built a city, he called the name of the city after the name of his son, Enoch. 18 To Enoch was born Irad, and Irad fathered Mehujael, and Mehujael fathered Methushael, and Methushael fathered Lamech. 19 And Lamech took two wives. The name of the one was Adah, and the name of the other Zillah. 20 Adah bore Jabal; he was the father of those who dwell in tents and have livestock. 21 His brother's name was Jubal; he was the father of all those who play the lyre and pipe. 22 Zillah also bore Tubal-cain; he was the forger of all instruments of bronze and iron. The sister of Tubal-cain was Naamah.
This records the abortive origins of civilization. Urbanization. Art. Technology. Because Cain can no longer make a living as a farmer, since his farmland is accursed, he has to change careers. And he feels the need to create his own city of refuge, a fortified settlement to protect him from his imagined pursuers.
Critics challenge how this can be correlated with the stone age, copper age, bronze age, iron age, &c. We need to keep several things in mind:
i) We need to distinguish between invention and cultural diffusion. Every invention is initially local. Know-how may or may not be disseminated in space and time. Some innovations occur in geographically isolated pockets where there is no cultural diffusion. It may be forgotten in a generation or so, then rediscovered somewhere else, at a later date.
By the same token, you can have multiple discoveries by independent inventors. Innovations don't all happen at the same time or place. Therefore, it's artificial to arrange "progress" in a single timeline, for "progress" isn't that linear.
ii) Add to that the random nature of what trace evidence survives, as well as what fraction of surviving evidence is found by archeologists.
iii) Moreover, we'd expect these technological breakthroughs to be obliterated by the flood. Postdiluvial society would have to start from scratch.
For an alternative explanation, see Collins.
iv) Narrative compression is a common technique in the historical writings of Scripture. Gen 4:17-21 may be a case in point. Consolidating events in a shorter timespan than was actually the case. That's not fictitious. Rather, it's a way of covering a lot of ground in a short space. Genesis doesn't presume to offer an exhaustive world history. It's narrowly selective.
v) Liberal commentators routinely dismiss the many "etiologies" of Genesis as legendary folklore. However, there really is a first time for everything, so there's nothing inherently suspect about saying so.
23 Lamech said to his wives:“Adah and Zillah, hear my voice; you wives of Lamech, listen to what I say:I have killed a man for wounding me, a young man for striking me.24 If Cain's revenge is sevenfold, then Lamech's is seventy-sevenfold.”
Another example of the moral freefall. Polygamy, and the cheapening of life.
25 And Adam knew his wife again, and she bore a son and called his name Seth, for she said, “God has appointed for me another offspring instead of Abel, for Cain killed him.”
That contains a miniature theodicy. Seth was the replacement child. He took the place of his murdered brother. Abel's death was tragic. Yet Abel's untimely demise made room for Seth. Absent Abel's premature death, Seth would not exist. What was evil for Abel was good for Seth.
We are shortsighted creatures. We think we can imagine ways the world might be better. But "improvements" have unforeseeable long-range consequences. A short-term good may be offset by an long-term evil. A short-term evil may be offset by a long-term good. Only God can balance out all the tradeoffs.
26 To Seth also a son was born, and he called his name Enosh. At that time people began to call upon the name of the Lord.
The inception of organized religion. A religious community. A community of fellow believers.
References:
Collins, J. Did Adam and Eve Really Exist? (Crossway 2011), 113-14.