I sometimes get questions about the remarkably long lives of the patriarchs who lived before the great flood. Consider some of their reported ages when they died:

Adam 930
Seth 912
Enosh 905
Jared 962
Methuselah 969
Noah 600
Shem 600
Eber 464
Abraham 175
Moses 120
David 70
...Personally, I think we need to take the stated ages of the patriarchs at face value and just accept it as a mystery: for some reason the ancient patriarchs lived far longer we do today. I cannot prove that the patriarchs actually lived that long, but neither is there strong evidence that they did not. Frankly, I have little stake in insisting that they did in fact live that long. I think it is best just to accept that they did.

...There is perhaps a theological truth hidden in the shrinking lifespans over the course of time in the Old Testament. Scripture links sin and death. The day they ate of the forbidden fruit of the Tree of the Knowledge of Good and Evil, Adam and Eve were warned that they would die (Gen 2:17). Yet they did not drop dead immediately. And although they died spiritually in an instant, the clock of death for their bodies wound down much later. As can be seen in the list of lifespans of the patriarchs (see above), as sin increased, lifespans dropped precipitously, especially after the flood.

Prior to the flood, lifespans remained in the vicinity of 900 years. Immediately afterward, they dropped by about a third (Noah and Shem only lived to be 600), and from there the numbers plummeted even further. Neither Abraham nor Moses even reached the age of 200, and by the time of King David, he would write, Our years are seventy, or eighty for those who are strong (Ps 90:10).

Scripture says, For the wages of sin is death (Rom 6:23). Indeed they are, especially in terms of lifespan. Perhaps that’s why I’m not too anxious to try to disprove the long lifespans of the patriarchs. What we know theologically is borne out in our human experience: sin is life-destroying. And this truth is surely writ large in the declining lifespan of the human family.

...How or even whether the patriarchs lived to be more than 900 years old is not clear. But what is theologically clear is that we don’t live that long today because of the collective effect of sin upon us.