In chapters 4 & 5 of Genesis two classes of men are described: those descended from Cain (ch 4); and those descended from Seth (ch 5). Details about the lives of both groups of descendants are fascinating and instructive.
Cain’s descendant Jabal was said to be, “the father of those who dwell in tents and have livestock” (4:20). Cain’s people were materially prosperous. Jubal was said to be, “the father of all those who play the lyre and pipe” (4:21). Cain’s people were talented musicians. Tubal-cain was, “the forger of all implements of bronze and iron” (4:22). Cain’s people were skilled in their trades. There is of course nothing wrong with being materially prosperous, a talented musician, or skilled in one’s trade. In fact such attributes are often due to admirable qualities like diligence and hard work.
However despite these seemingly positive traits about Cain’s descendants, they were a godless people who were not interested in doing what God said. In fact some, such as Lamech, were characterized solely by their moral viciousness (4:23-24) Cain himself was a man who had offered a displeasing sacrifice to God and was guilty of the first murder in human history when he killed his brother Abel (4:5,8). The fact that this is all that can be said about Cain’s descendants shows that they are utterly lacking in the most important area.
Contrast Cain’s people with those descended from Seth, who would eventually become God’s chosen people. Details about their lives were relatively simple. Nowhere do we read about their wealth or talent. Instead we see evidence of their high regard for God and what He said. These people, “called upon the name of the Lord” (4:26). This is a way of describing one’s high regard for God and intense desire to worship Him. Descendants like Enoch are simply said to have, “walked with God” (5:22).
People of the world may measure themselves by their wealth, talent, or skills. But God’s people are concerned with doing one thing above all the rest: walking with God. Seth’s descendants were not chosen simply because of their bloodline. They were God’s people because of their regard for Him and His will. We too can be God’s people if we do what He says.