Genesis 4:17-26

Cain had marital relations with his wife, and she became pregnant and gave birth to Enoch. Cain was building a city, and he named the city after his son Enoch. 18 To Enoch was born Irad, and Irad was the father of Mehujael. Mehujael was the father of Methushael, and Methushael was the father of Lamech.

19 Lamech took two wives for himself; the name of the first was Adah, and the name of the second was Zillah. 20 Adah gave birth to Jabal; he was the first of those who live in tents and keep livestock. 21 The name of his brother was Jubal; he was the first of all who play the harp and the flute. 22 Now Zillah also gave birth to Tubal-Cain, who heated metal and shaped all kinds of tools made of bronze and iron. The sister of Tubal-Cain was Naamah.

23 Lamech said to his wives,
“Adah and Zillah! Listen to me!
You wives of Lamech, hear my words!
I have killed a man for wounding me,
a young man for hurting me.
24 If Cain is to be avenged seven times as much,
then Lamech seventy-seven times!”

Just because something is in the Bible does not mean it is being advocated. With regard to this Lamech, mention is made that he took two wives. Polygamy is not as widespread in the Old Testament as many seem to imagine. When it is mentioned, there is usually some sort of trouble associated with that choice. Polygamy is not being explicitly criticized here, but neither is it being condoned or recommended.

Even more noteworthy is Lamech’s attitude toward others. He has a high opinion of himself and declares that he deserves to be avenged many times over for any harm done to him.

Perhaps it is God’s way of commenting on Lamech that the scripture passage makes no further mention of his descendants, beyond his children.

25 And Adam had marital relations with his wife again, and she gave birth to a son. She named him Seth, saying, “God has given me another child in place of Abel because Cain killed him.” 26 And a son was also born to Seth, whom he named Enosh. At that time people began to worship the LORD.

It is not clear what, exactly, the end of verse 26 is referring to. Abel worshiped God when he brought his offering to Him, so worship of God goes back at least to Abel. But Cain killed him, and Cain’s family, as a whole, may have given God short-shrift. Perhaps the arrival of Seth and his family represented a shift toward greater reverence for God, but this is speculation. “Worship” is, in the Hebrew, “call in the name.” For references to Abraham calling on the name of the LORD see Gen. 12:8, 13:4 and 21:33.