Misinterpreting Genesis 6:3 can easily lead to the belief that the Bible has errors. In the verse, God says, "My Spirit shall not abide in man forever, for he is flesh: his days shall be 120 years." Is God saying mankind will never live past 120? Considering Noah was 600 at the time of the Flood and lived another 350 years, this is problematic. The next several generations saw men live to the ages of 500, 403, and 207. Granted, Moses lived to 120, and since then very few have lived longer. But it has happened, and Moses was born several hundred years after this promise. So what does this verse mean?
Does the Bible give a human age limit?
First, the context. This was before the Flood, when ages regularly reached into the 900s. The people were evil (hence God's reluctance to "abide in" them or "contend" with them). They were so evil God decided to wipe the slate clean, so to speak, and restart the human race. It is more likely that Genesis 6:3 gave a countdown to the arrival of the Flood.
There is some resistance to this interpretation. In Genesis 5:32, Noah's age is given at 500. He was 600 when the Flood came, leaving a span of only 100 years, not 120. But Genesis 5:32 is the last verse in a line of genealogies, giving men's ages at the birth of their sons and their deaths. It doesn't have anything to do with the timing of the Flood. Genesis 6 is a return to the narrative, which doesn't necessarily directly follow chapter 5. So the text takes a break from the story to give the genealogy from Adam to Noah (common in the Bible), and then goes back to the story. Meaning that from Genesis 6:3, God would only allow 120 years before He destroyed the evil people. He then waited until after Noah's sons were born before commissioning Noah to build the ark.
Another passage that seems to indicate a human age limit is Psalm 90:10, written by Moses: "The years of our life are seventy, or even by reason of strength eighty …" The verse seems to say that humans can only live to 70 or 80 — a strange sentiment from someone who lived to 120. But the Psalms are meant to express spiritual truths, not necessarily scientific facts. This psalm is about the fragility of human life in the face of God's anger over our sin.
The second half of the verse says: "yet their span is but toil and trouble; they are soon gone, and we fly away." While some lives are characterized by constant "toil and trouble," this is not a universal human experience. And the image of the dead flying away, while metaphorical, isn't exactly literal. Like in modern poetry, Moses is using metaphors to express truths, not facts.
It is possible that Genesis 6:3 is a general truism meaning mankind would eventually get to the point where 120 is a cut-off for the vast majority of us. But it's more likely that it was a countdown for the wicked of the earth who would be destroyed by the Flood.
Is there any way to guarantee ourselves a long life on earth?
Why are such long lives recorded in Genesis?
Can man live without God?
Questions about Noah's ark: How long did it take Noah to build the ark? How long was Noah on the ark?
What was the effect of the fall on humanity? How did the fall affect our world?
Truth about Humanity