Be Fruitful and Multiply
A fellow believer posed the following question, and I decided to analyze the Scriptures from a mathematical perspective to provide my response.
In the beginning, God created the first humans, Adam and Eve. With whom did their sons and daughters have children?
The answer is obvious, but our modern society cannot fathom brother and sister marriages for the sole fact of incest. Yet, the Scriptures tolerated sibling marriages because the famous patriarch, Abraham, married Sarah, his sister, as noted in Genesis 20:12. However, we read that God commanded Adam and Eve to reproduce by equipping them with a blessing for such an endeavor. Then God blessed them, and God said to them, Be fruitful and multiply; fill the earth and subdue it. (Genesis 1:38) God created only two human beings, Adam and Eve, and directed them to have many children by the command, Fill the earth! Yet, Scripture mentioned only three of Adam's and Eve's children by name (Cain, Abel, and Seth). Since Scripture failed to record the names of all the children, one can easily infer that others children originated from this union because Adam was 130 years old when his wife gave birth to Seth, and he lived another 800 years afterward. (Genesis 5:3-4) Obviously, the couple had children before and after Seth because Scripture states that Adam had sons and daughters (Genesis 5:3). Scriptures fail to provide the names because the focus rests on Seth as the unique son. For God, said she, hath appointed me another seed instead of Abel, whom Cain slew (Genesis 4:25). Subsequently, the Scripture recorded the lineage of Adam through Seth. For instance, during Adam's life span, he conversed with his son, Seth, for 800 years;
his grandson, Enos, for 695 years;
his great grandson, Cainan, for 605 years;
his great, great grandson, Mahalalee, for 535 years;
his great, great, great, grandson Jared, for 470 years;
his great, great, great, great, grandson, Enoch, for 308 years,
his great, great, great, great, great, grandson, Methusaleh, for 243 years, and finally, Lamech 56 years, who is the son of Methusaleh (six generations from Adam).
Such a lifespan is unheard of today. But, nonetheless, I see my ancestry tree as very inconsequential when comparing. For instance, I lived 31 years with my grandfather, Locy, and 55 years with my father, Comer, and before my birth, my great-grandfather, Will Baker, passed away, so I never got to meet him. Yet, it is astounding to think that Adam lived to see six generations of children during his lifetime, whereas we might see three generations today.
In Genesis, the average life expectancy was ten times higher before the Flood occurred. Likewise, the fertility period for the women in Genesis could have easily extended to the age of 350 compared to the age of 50 by today's standard. Adam and Eve could easily have had 50 children if childbirth had occurred every seven years. Then, if each married couple had 50 more children within the next 350 years, 25 couples x 50 children would equal 1250 offspring within the first generation alone. If you multiply this number by six generations, the number of children could reach 7,500 before Adam died. Please note that my calculation consists of a childbirth every seven years. If a birth occurred every nine months, this number would explode into thousands of offspring of Adam during his lifespan. Can you imagine how many grandchildren and great-grandchildren Adam got to meet?
In 1960, the world population equated to 3 billion people, and 61 years later, the population increased to 7.8 billion. By 2050, the projected population will equal 9.8 billion. Considering these facts alone, it is evident that humanity is filling the earth following God's plan. Furthermore, since the genetic pool in Genesis for the first family is flawless, the early population of humanity occurred with no congenital disabilities or disorders, allowing the expansion to increase expeditiously. In my opinion, Adam's and Eve's offspring had a massive selection of marriage choices, and they fulfill the command to be fruitful and multiply easily.
Then God blessed them, and God said to them, Be fruitful and multiply; fill the earth and subdue it. (Genesis 1:38)