Genesis 4:17

• Cain’s wife was probably one of his sisters (5:4). Cain’s marriage to his sister would not have caused genetic problems so early in the development of the human gene pool.

• God condemned Cain to be a wanderer. He might have built a city to rebel against this punishment, using walls for protection. Naming the city after his son shows how people who rebel against God often make humanity and its achievements into idols.

These records of family lines do more than just list names. They contrast how human culture developed. Some people rebelled against God (Cain, 4:17–24), while others obeyed God (Seth, 4:25–5:32). Genesis usually explains the history of the rejected line before continuing with the promised line that became Israel.

Two key contrasts are worth noting:

1. Lamech is the main focus of the first family history. He is the seventh man from Adam through Cain's line. Like Cain, Lamech killed a human and lived in fear of death as a result (4:23–24). In contrast, Enoch lived in a way that pleased God and did not experience death (5:24). Enoch was the seventh man from Adam through Seth's line (4:25–5:32).

2. Human culture and technology advanced through Cain’s line. They made the first city, raised livestock, built shelters, developed metal work, and created music. But sin still strongly shaped human life. Seth's line does not have any technological advances mentioned. Instead, people began "to call upon the name of the LORD" (4:26) and "found favor in the eyes of the Lord" (6:8).