Genesis 4

10–12 To punish Cain, God placed him under a curse (verse 11). No longer would the land give Cain food and sustenance. Not only that, the land would no longer give him settlement; he would never be able to settle down but would become a restless wanderer forced to move from place to place.

13–16 Cain responded to this punishment with self-pity and remorse,²⁴ but not with true REPENTANCE. Yet even though Cain was unrepentant, God continued to show mercy to him. Since Cain would not have the protection of a settled community, he naturally feared for his life. So God promised to protect him, and to do so He placed a mark on him (verse 15). It is not known what this “mark” was.²⁵ But anyone who sought to kill Cain would somehow recognize the mark, and know that Cain was under God’s protection.

Then Cain left the LORD’s presence (verse 16)—the Lord’s fellowship—and headed east to the land of Nod, whose location is unknown.

17–24 Where did Cain find a wife? (verse 17). The simple answer is that Adam and Eve must have had one or more daughters, and that Cain married one of his sisters.

In verse 23, we encounter the first instance of polygamy in history; Lamech, one of Cain’s descendants, had two wives. Here, after telling his wives how he has killed a man, Lamech compares his situation with Cain s. Cain had murdered his brother who was innocent; Lamech had killed a man because the man had injured him. Cain’s crime was greater. Therefore, if God says that Cain’s killer will suffer vengeance seven times over (verse 15), then Lamech argues that he—who committed a lesser crime—should be avenged seventy-seven times²⁶ (verse 24).

Lamech was wrong to have taken vengeance on the man who had injured him. Vengeance belongs to the Lord alone; we humans must not take vengeance into our own hands. “It is mine to avenge,” says the Lord; “I will repay” (Deuteronomy 32:35; Romans 12:19–21).

25–26 Throughout the book of Genesis, great emphasis is placed on offspring, especially on the offspring which will result in the founding of ISRAEL and, ultimately, in the birth of the Messiah, Christ (see Genesis 3:14–15 and comment). From among the offspring, it is God who chooses which one will carry on the family line leading to Christ. Adam and Eve’s third son, Seth, was the one chosen.

As Seth’s descendants increased in number, they began to call on the name of the LORD (verse 26)—that is, to depend on the Lord, to believe in Him. This was in contrast to the descendants of Cain, who showed no such dependence or faith. Yet Cain’s descendants developed many useful skills (verses 20–22), which contributed to the beginnings of modern civilization.

Today we pride ourselves on such skills—modern technology, gleaming skyscrapers, the exploration of space. Yet if we turn from God, all our accomplishments will in the end come to nothing, just as Cain’s city and all of his descendants came to nothing in the Flood (Genesis 7:17–23). The world and its desires pass away, but the man who does the will of God lives forever (1 John 2:17).