The Fall of man resulted in the Covenant of Works being broken, but God did not leave matters there. If man was to have the intimate, eternal communion with God for which he had been made, then the initiative for bringing that about would have to come from God by His grace. Grace is God’s unmerited favor toward man; indeed, it is God’s favor despite man’s demonstrated demerit. Even in the curses God pronounces in judgment (3:14-20), there are elements of grace. In this, we see the beginnings of the Covenant of Grace, which encompasses the rest of Scripture and centers on Christ. The curses on Adam and Eve—toilsome labor and difficulty in childbirth—reflect a postponement in the execution of God’s decree of death for their sin and will force the couple to place their faith upon God in everyday life. More importantly, in the curse on the serpent God announces there will be enmity between the seed of the serpent and the seed of Eve, and that a Seed of Eve will someday crush the head of the serpent, even while being bruised by him (3:15). This is the first prophecy of a redeemer who will save mankind from the consequences of the broken Covenant of Works.
This promised Seed is probably in Eve’s mind when she gives birth to her firstborn child, Cain, and says she has acquired a man from the LORD (4:1). Cain hardly is a deliverer though. The biblical account focuses on the differing sacrifices of Cain and Abel and Cain’s subsequent murder of Abel in a fit of jealousy. Many commentators observe the typological parallelism of Abel as a type of Christ, as well as the idea that Abel’s offering was of a blood sacrifice, anticipating the sacrifice that Christ would make in dying on the cross. More, however, can be said in terms of the covenantal significance of Gen. 4:1-6:8. This passage speaks of both the nature of man, the nature of God, and the way God has chosen to engage with man under the Covenant of Grace.
The account of the offerings made by Cain and Abel establish a key point about how man is to approach God, namely with reverence, humility, and awareness of one’s own sin. The Hebrew word used for offering in Gen. 4 is one that also is used to describe the offering of tribute to kings. In offering tribute, there is the presumption of rendering honor to one’s superior. Abel, in his offering, provides the firstborn of his flock; with Cain, Scripture records that he merely gave an offering (4:3-40). The Genesis account does not provide a reason why God accepted Abel’s offering, but rejected Cain’s, but the original readers probably would have understood that from the nature of the offerings, seeing the offerings as both antecedent to and in continuity with the sacrificial system God instituted after the Exodus. A burnt offering, like what Abel probably made, was done for making atonement for sin; a grain offering, however; was a fellowship offering. Abel therefore came to God acknowledging his sin and seeking atonement, whereas Cain presumed fellowship with God without that. It was the heart attitude that was behind whether or not God accepted the offerings. Abel demonstrated reverence, awe, and humility before the LORD. Cain did not, and that led to the LORD’s rebuke (4:7).
The account of Cain and Abel tells us something of the character and work of God as well. God exhibits grace in rebuking Cain and warning him that sin is crouching at his door (4:7). After Cain murders his brother, God demonstrates that He is a just king, seeking justice for the victim. Yet even this is tempered with mercy, in that while Cain’s own death could have been required as retribution, God spares him and sends him into exile, putting a mark on him so that he will not be killed by others. God’s purpose in acting that way is not immediately obvious, but is implicit in the genealogies that follow. Genesis 4:16-24 lists the descendants of Cain and 4:25-5:32 the descendants from the next child of Adam and Eve, Seth. God’s overarching plan involves progress toward fulfilling the original cultural mandate, of man multiplying and having dominion and that requires providentially preserving mankind. God has chosen to work through the course of history in His dealings with man, moving man toward the final (eschatological) end that He intended from the outset. The contrast between the ungodly line of Cain and the godly line of Seth shows a principle of differentiation also at work in history; as mankind grows, God is drawing out a people for Himself. The presumptuous rebelliousness of Cain’s descendants is shown by Lamech’s arrogant violence (4:23-24), while God’s blessedness on Adam’s line is evident in the longevity of the patriarchs, and especially in the fact that Enoch was taken to God without dying (5:24). This is the beginning of redemptive history.