Have you ever wondered where, exactly, your genes came from? How often do people ask the parents, of their children, “Where did your child get that gorgeous red hair?” or “Does athleticism run in your family?”
On the other hand, how often has someone wondered why they are as different as can be from the family they were born into, or raised up in? Ancestry.com has a robust trade in processing clients’ DNA, and giving them background information on what people groups and geographical areas are represented in their genes. Sometimes there a big surprises.
And what about personality, character traits, gender, all the differences and similarities found in families, and among people groups? How much can be attributed to nature? How much to nurture? To date, research in neither the biological nor the social sciences has been able to resolve the nature/nurture question regarding those kind of differences. The greatest single factor for this is our cerebral cortex—we are amazingly able to learn, grow, mimic, adapt, and adopt.
Which brings us to the matter of faith.
The ancient Hebrews did not always intend their genealogies to be used as a chronology.  Often, names were left out of a genealogy in order to produce symmetry, a neat and clean pattern. The primary purpose of the genealogy was to establish a person’s family identity, a person’s roots. Often, only the most well-known names were chosen. Because there is symmetry in both Cain’s and Seth’s genealogies, part of what you and I can gain from these passages is in comparing them.
Seth’s genealogy and Cain’s are remarkably different. Cain’s included no ages, no gravestones, and no mention of God, just accomplishments and perversions. Seth’s, on the other hand, has no accomplishments at all, plenty of gravestones, and amazingly long life spans. The most noteworthy thing you could say about any of the people in Seth’s line is that they were people of faith, and a people of long life. It’s as though nothing else counted to them but their relationship with God, and how life-giving that relationship was.
Some commentaries have sought to explain the unusually long life spans by suggesting the years are really months, but that would mean Enoch was 5 years old when he fathered Methuselah, so that doesn’t really work.
Others have noted the easiest, if somewhat unscientific, approach is to accept the simplest reading of the text as true, they just lived a long time. This argument suggests that perhaps sin progressively corrupted the world. Our world today, the argument continues, is not like the world Adam and Eve first brought their children and grandchildren into.
These scholars would contend scripture indicates God numbers the days of each person; therefore, perhaps God permitted a very long age for early humankind, and has numbered the days of humankind today to a much shorter life span. To help support this contention, a cryptic saying of God’s is pointed out in Genesis 6:3, that seems to indicate God established an outer limit to human aging.
Several commentators propose the names listed here are actually clans, or family groups, instead of individuals, even though scripture does talk about these people as being actual people. It is still certainly possible to take this view, as even today we see those we love live on in the memories, traits, and habits of their children, grandchildren, and even great grandchildren.
However way we understand these unusually long lifespans, whether as actual lengths of life, ages counted in units other than years, or representing clans fathered by each name, the underlying truth of longevity comes through. These were a people whose lives, centered around God, were lived in stability and peace, in health and good care.
Cain’s culture exalted the self and devalued others.
Seth’s line exalted God and viewed the frailty and mortality of humankind with a sense of compassion, having been made in God’s image, as the beginning of Genesis chapter 5 indicates, “This is the written account of Adam’s family line. When God created humankind, He made them in the likeness of God.” Remember that “adam” in Hebrew is a neutral word meaning human or “person.”
Together, men and women make up what in Hebrew is called “adam,” which the writer of Genesis elucidated, “[God] created them male and female and blessed them. And He named them “Humankind” when they were created.” Then the man, Adam, “…had a son in his own likeness, in his own image; and he named him Seth.” There is a link between these two verses. Though Seth, Adam’s son, had received the imprint of God’s image, the likeness God put on all people when He created them and called them “very good” … he also received the imprint of his father’s image — whether by nature, or by nurture — that everyone to this day ends up with.
It’s a mixed nature, one of dignity and depravity, and we see the struggle in all humankind from Seth’s and Cain’s day to this day today.
[Seth’s Geneology, Drnhawkins [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]