The introduction to Cain’s family began in verse 17. But before continuing down his line, let’s jump over to verse 25 where we find Seth introduced. Eve named him Seth because the name means to set or appoint a person, and Eve said Seth was appointed to replace Abel. That statement may be a little confusing. From the nature of the sacrifices earlier in the chapter, it had appeared that Cain and Abel were relatively young men. Let’s presume for a moment that they were then about 30 years old. That means that Adam was only slightly older, probably having the boys when he was only 1 or 2 years into his existence. But Seth, we are told in chapter 5 verse 3, is born when Adam was 130 years old! The timing just doesn’t make sense for Eve to consider Seth a replacement for Abel. Did Adam and Eve wait around about 100 years before having another child? Probably not. But if our presumption was wrong and Cain and Abel were about 130 rather than 30 when Abel was murdered, and Adam and Eve surely had many sons and daughters in that time, would it not seem odd that Eve considered Seth a replacement for Abel when she already had so many other children?

The mention of Seth here (without mentioning any of the other children Adam and Eve had) and assigning him the title of replacement may have to do with something more than mere replacement of the count of children. Abel had been one (based on the story of his offering) who had pursued God rightly and with zeal. He seemed to image God as God had wanted his image bearers to be. Perhaps the statement Eve made about Seth has to do with him imaging and pursuing God in the same fashion as had Abel. Therefore, we don’t have to worry about anybody’s age when trying to understand how Seth replaced Abel; we rather see the focus of the text is on how Seth followed God. And so Seth takes up the contrast to Cain replacing Abel, whose good had formerly been used to contrast with Cain’s evil. And in this sense, then, Cain continues to symbolize the world at large while Seth becomes the focal point of the group at the Garden gate symbolizing Israel, both because of location by God’s earthly dwelling and because of Seth’s nature as God-desiring image bearer.

Again, we should note between these two groups or family lines the primary focus of each. Cain’s family has primary concern with that which is physical while Seth’s family shows primary concern for the spiritual. Here’s what I mean: we are told that Cain built a city and dedicated his work to his offspring. His son’s name is Enoch, which means dedicated. And in this, I think, we are meant to see the same focus that Cain had back when he brought his offering to God. Cain meant the offering to showcase his work—what he had produced. With the building of the city (his work; his production), we have no look to God but mere focus and promotion of Cain’s son, whom he also produced, linking his son to the city—a physical focus.

Let’s move forward to Seth now. He too has a son born to him whom he names Enosh. Enosh means men. The Bible definitely links this name for men with the immediately given statement that men began to call on the name of Yahweh. In fact, although in our English translations, we have two sentences made out of verse 26 (with mention of “Enosh” and mention of either “men” or “people,” the Hebrew has but the name of Enosh, intimating a connection with the men who would call on the name of Yahweh.

We may also wonder why it was not until the time of Seth (when Adam was already over 130 years old) when people started calling on the name of Yahweh. Again, the text helps with hints of an answer. In Genesis 1, God was called Elohim, the mighty one. In chapters 2 and 3, God is called Yahweh Elohim, highlighting the mighty one with the more relational name of Yahweh. But here in chapter four, God is referred to as simply Yahweh, the intimate name. All these children to Adam and Eve grew up without the close connection Adam and Eve had enjoyed in the Garden. And although they may have paused on the Sabbath to worship, their lives were consumed with trying to scratch out a living with no grocery stores, no ready-made farming fields and barns, nor even any tools with which to build anything. They literally started from scratch, turning every day into a difficult struggle to merely survive. It would be easy without the Holy Spirit’s presence inside and without a single text of support in how to live to have attention turned to God (despite Adam and Eve’s probable reminders now and then). What we see then with Seth is someone who does concentrate on turning his attention to God (as Abel had), and apparently influences his children—his generational line—to start doing the same.

The descendants listed in Cain’s line are fewer than those listed in Seth’s line. The reason is most probably because the lines are meant to end with two men, one from each line, who share the same name: Lamech. The Lamech of Cain’s descendants shows his disregard of God, the trait of Cain’s family line, in taking two wives. While the Bible rarely records God’s displeasure of polygamy, the specific emphasis in the essence unity imaged by the one man-one woman of Genesis 2 gives support to the marriage image God intended. But that image is violated by Lamech.

Attention then centers on Lamech’s children. Notice the emphasis: Jabal is a herdsman, Jubal is a musician, and Tubal-cain is a toolsmith. The concentration still is on the physical. Although, of course, physical labor is necessary to continue life, the point is that dependence on God is more necessary. And the comment that Jubal “was the father of all who play the lyre and the flute” gains effective poignancy when the reader suddenly realizes that all those who would play the lyre and flute from Jubal’s influence would lose their lives in the flood.

Let’s shift again to Seth’s line. His descendant Lamech fathers Noah. Upon Noah’s birth, Lamech calls out in hope that this one would “bring us relief from the agonizing labor of our hands, caused by the ground the Lord has cursed.” His statement shows a trust in the promised hope that God had given back in chapter 3 regarding the crushing of the serpent. It is sure proof that Adam and Eve’s message to their descendants was full of dependent hope on God, backing Eve’s pleasure at getting a son (Seth) who cared for God. And therefore, we see the contrast of Seth’s line, interested in calling on Yahweh, as opposed to Cain’s line, interested more exclusively on the occupation of this life.

Finally, Cain’s Lamech makes a speech regarding the fact that he has killed someone. He attempts to defend himself by saying he acted in response to an attack. Whether his attacker had murder in mind is not clear. Nor is it even clear whether his attacker was in the wrong. But Lamech argues that since Cain received protection when Cain was not even attacked, he deserves protection of life more so since he killed because he was struck. The downward contrast should be clear. Whereas it was God who provided the mark offering protection for Cain for his specific purpose, Lamech demands the right to life without concern for God’s purpose.

In contrast, Seth’s Lamech makes no such claim for life, but by reviewing the genealogy, we find that God ends his life in a seemingly merciful way. By the ages of the descendants at the times they had their offspring, we can calculate that the flood occurred 1656 years into the world’s existence. Lamech died at the relatively (to others of his time) young age of 777, five years before the flood that puts to death the world of unbelievers. (Interestingly, Lamech’s father, Methuselah, the person who lived longest in this pre-flood era, died in the year of the flood, presumably, in it.