Two Brothers (Genesis 4)
The sin of Adam and Eve would have tragic consequences that would become evident in their very own family. Indeed, the larger human family has repeatedly duplicated the dysfunctional dynamics that sin produced in the first human family. A thoughtful consideration of the story of Cain and Abel yields some interesting lessons.
Adam and Eve had two sons-Cain, the firstborn, and Abel. (They would also have other sons and daughters, too, as mentioned in Genesis 5:4. Yet they apparently had no other sons until the death of Abel, as Seth seems to be the next male child in line, compare v. 25). Cain, we are told, became a tiller of the ground, a farmer. Abel became a shepherd. As to the acceptance of Abel's offering and the rejection of Cain's, some have suggested that there was something wrong in Cain bringing a grain offering. Yet we later see grain offerings as perfectly acceptable to God. Indeed, God said the grain offering was to be burnt "on the altar for a sweet aroma, as a memorial to the Lord. It is most holy, like the sin offering and the trespass offering" (Leviticus 6:15, 17). So what was the problem? Genesis 4:4 tells us that Abel brought from the "firstlings" of his flock, but no such indication of giving God the first or best is attached to Cain's offering in the previous verse. Perhaps this was due to Cain's overall attitude. Verse 5 states, "But [God] did not respect Cain and his offering." Notice that it was not just the offering that God did not respect, but Cain himself! Indeed, that may be the very reason that God did not accept his offering. We are often told in Scripture that God loathes the sacrifices, festivals and even prayers of those who are guilty of great wrong and yet are unrepentant (see Isaiah 1:10-15). When such a person "offers a grain offering, [it is] as if he offers swine's blood" (Isaiah 66:3). God recognized that Cain was on the verge of allowing sin to control him (verse 7)-to manifest itself in real action.
We are told that Abel, on the other hand, offered a better sacrifice because it was offered by faith, through which he was considered righteous (Hebrews 11:4; Matthew 23:35). Faith comes by hearing God's instruction (Romans 10:17). God's commandments must have been transmitted through Adam and Eve. And God must have even prescribed rules for worship at some point, or else how would Cain and Abel have known to bring sacrifices? Abel was obedient-through faith.
Cain's rejection roused him to anger and jealousy-though he may have already had these emotions to some degree. In any event, he did not master his urges, as God told him to (verse 7). Instead, he murdered his brother. Later, God confronted Cain: "The voice of your brother's blood cries out to Me from the ground" (verse 10). When someone is said to cry out to God, the cries are usually for relief, protection or vengeance. Abel's blood, figuratively speaking, cried out for vengeance. This is confirmed by Cain's fear that vengeance would be taken out upon him by anyone who found him, and by God's remarks in verse 15, which explicitly connect vengeance with the context. This is interesting because the book of Hebrews states that the blood of Jesus "speaks better things than that of Abel" (Hebrews 12:24). Why? Because Abel's blood sought vengeance, which was well and just, but Christ's blood offers mercy and forgiveness to those who will accept it, which is better.
Cain departed and headed east to the land of Nod, meaning "vagabond" or "wandering"-thus perhaps not indicating an actual geographic name. And then we see mention of Cain's wife, who must have been one of his sisters. "The problems associated with incest, addressed in Lev. 18, would not have occurred when the genetic pool was pure and unpolluted" (Nelson Study Bible, note on Genesis 5:4). Today, as defined by God in Leviticus 18, incest is a sin.