In Genesis 1-2, the origins of humanity are described. Mankind is made in God’s image and so man and woman have the breath of God within them. God blesses them and provides for them. They have meaning and purpose as they are told to fill and subdue the earth. And yet in Geneis 3 we discover that all has gone horribly wrong. Adam and Eve disobey God bringing about The Fall. The land is cursed and now Adam and Eve are subjected to death.
Romans 5:12 sums it up this way:
Sin came into the world through one man, and death through sin, and so death spread to all men because all sinned
Now in Genesis 4-5, the author begins to show exactly how sin and death come to all men from Adam. Adam and Eve have children and that is cause for hope following the darkness of exile from Eden but can their offspring escape their fate?
Children, hope and forboding
Genesis 4 begins the story of Adam’s descendants beginning with his two firstborn sons. Eve conceives and bares Cain first. Hebrew loves word play and draws a connection between his name and the verb to acquire. Eve’s naming of her son is a prayer of thanks, cain is a son, a man acquired from God. Eve recognises God’s grace in the aftermath of the Fall. She may be the mother of life but God is the giver of life (v1).
She conceives a second time and this son is called Abel. Notice the link to the Hebrew word for breath of vapour. This is the word used by Qoheleth in Ecclesiastes to assess life under the sun, it is all abel – breath, air, vapour. Does this point to Abel as an afterthought, maybe even to weakness and fragility? Possibly, but it could also an awareness on Eve’s part of the fragility of life or even more positively that it is God who gives breath and life (v2).
The two young men grow up to be farmers obeying the cultural mandate to subdue the earth and taking on the responsibility of tending or tilling and keeping. Responsibilities are divided, Cain tills the land whilst Abel keeps animals. Then one day, they decide to bring their offerings to God. Cain brings some of his produce and Abel brings an offering from the flock only with Abel it is specified that he brings the firstborn and it’s the fatty or choice portions that he offers. God has regard, or looks with favour on Abel’s offering but not Cain’s. I think we can detect something of an understatement there. God is choosing Abel’s offering over Cain’s. The older brother’s gift is rejected in favour of the younger one’s (v3-5).
Why does God accept Abel’s offering? Well, there is perhaps something to be made of in that Abel brings the best, he brings the firstborn. This is an act of faith. Cain does not seem to take the same step of faith or gratitude to God. However, I also think that there is a recognition in Abel of need. Scripture sets out the method of atonement as being through sacrifice and so Abel brings a sacrifice. Would it have been fair for God to expect the brothers to know this or does Abel just get lucky? I want to suggest that this is about more than luck and is about obedience as Abel follows a patter.
In Genesis 3, Adam and Eve had attempted to cover their shame and guilt by making clothing from fig leaves. Their attempt was futile and so they hid from God. Yet they could not avoid having their guilt, nakedness and shame exposed. So, God acted to cover their shame and nakedness with animal skins. God in Genesis 3 has modelled the necessary atonement offering that covers shame and enables access into his presence. Abel gets that, Cain doesn’t.
Jealousy, anger and …
Cain’s reaction is anger, his face is down-cast and God finds him in this state (v5b-6). “Why are you angry and downcast?” He asks, echoing the questions in Genesis 3 “Where are you” and “Who told you?” with the implicit partner question “why are you hiding?” God invites Cain, pleads with him to do well, what is right in order that he might be accepted. The promise here is effect that the regard not shown to his offering can be shown to a good and righteous life. However, he is warned that sin waits to tempt and attack, it is portrayed as a dangerous enemy at the gate, poised and ready to pounce. Note that the structure of sin’s desire towards Cain contrasted with the duty on him to master it echoes the language in Genesis 3 of the woman’s desire towards the man being countered by his mastering her.
English translations smooth out v8 so that we read that “Cain spoke to Abel.” That does leave the exact nature of the conversation in question. However, in Hebrew it is literally “Cain said to his brother, Abel … and when they were in the field.” The incomplete sentence that beings “Cain said” reinforces the sense of an interrupted conversation and a broken relationship. Out in the field Cain murders his brother. 
Just as in Genesis 3, God comes looking and asking “where is” this time not “Where are you?” but “where is your brother? (v9). It is not that God does not know but that God is challenging Cain, calling upon him for confession. Cain lies “I do not know.” Fascinating isn’t it that sin which is meant to lead to knowledge leads to the denial of knowledge and the embracing of ignorance. Like his parents, he tries to shift responsibility and absolve himself; “am I my brother’s keeper.” If there is a keeping, caring, guarding responsibility on Cain as man, then as far as he is concerned it is limited to his responsibility to the land and does not extend to his flesh and blood.
God does know and will not allow Cain to absolve himself. He challenges Cain again to confess to what he has done. Note the vivid language describing Abel’s blood crying out from the land and if it is from the earth then it is calling out from the place of Cain’s domain and responsibility (v10). If in Genesis 3, God restricted himself to pronouncing the ground and the serpent cursed, here too he describes Cain as explicitly cursed (v11). He is cursed from the land implying exile from it, not just from the garden but alienated from the land itself. This is another way of describing death. The penalty for Abel’s murder is Cain’s death, not the immediate loss of physical life but the death of exile, alienation and curse. He will experience greater struggle and toil still. It seems that he will no longer be able to farm but as a fugitive he will be condemned to wandering and scavenging (v12)
Cain considers this punishment unbearable. It’s too much for him (v13-14). The punishment will drive him away from his calling and vocation but also he fears that there is now a target on his back, that he will be vulnerable to vengeance because being away from the land means being away from settlement and safety. However, God insists that this will not be so (v15). God marks Cain and promises that he will bring sevenfold vengeance on anyone who attacks him. The number 7 here symbolises completeness so we may surmise that the vengeance will be total, wiping out their family line. Here by putting protection on Cain, God makes it clear that justice is bounded. It is not for anyone to do as they please and it is finite so that ongoing and perennial blood feuds are not permitted.
Sin spreads and grows
Genesis 4 shows us that Cain has inherited his father’s sinful nature. Desire and disobedience in chapter 3 has developed into murder. It is not just that the propensity to sin has been passed on but the nature of evil has intensified.
However, whilst it is right to focus on the specific sin of murder here, it is important to notice two things. First of all that this sin is accompanied by other sins, one sin rarely comes on its own but tends to cluster with other related desires. Secondly, notice that for Cain, sin is worked out in the act of killing but it arises out of a heart condition so that Jesus rightly identifies the problem of murder as something within the human heart. So murder arises out of jealousy and hatred and leads to or is accompanied by deceit and lying.
Can and his descendants are subject to sin’s rule and therefore are subjected to its consequences. Genesis 5 goes on to list the descendants of Adam, each marries and has children but with one exception, Enoch, we are told that they died so that “and he died” is the refrain that dominates the text. Humans were meant to live for ever but now death has become unavoidable. It is not just that we seek to kill others but that we have brought death on ourselves, we have killed ourselves.
 Gordon Wenham, Genesis 1-15 (Word Biblical Commentary. 1987), 101.
 Wenham, Genesis 1-15, 102.
 Wenham sees a foreshadowing in the name of Abel’s life being cut short. Wenham, Genesis 1-15, 102.See also, Peter Williams, From Eden to Egypt: Exploring the Genesis Themes, (Epsom, Surrey. Day One Publications, 2001),
 Wenham, Genesis 1-15, 103.
 C.f. Wenham, Genesis 1-15, 106.
 C.f. Barry Bandstra, Genesis 1-11: A handbook on the Hebrew text (Waco, Tx.: Baylor University Press, 2008), 243.
 Wenham, Genesis 1-15, 106.
 Peter Williams, From Eden to Egypt: Exploring the Genesis Themes, (Epsom, Surrey. Day One Publications, 2001), 40.
 Wenham, Genesis 1-15,106.
 Wenham, Genesis 1-15,107.