Q. In regards to a generation of years, God stated that no one would live longer than 120 years after the great flood. As far as I am aware some individuals have come to live very close to 120 years but not to 120. So does this mean that the average life span could be longer than 70-80?
A. The Bible does not say man’s life span would be limited to 120 years, and in fact several post flood generations lived longer that that. Genesis 11:10-32 recounts the generations from Shem to Abraham, all of whom lived substantially longer than 120 years. Abraham himself lived to be 175 years old (Genesis 25:7). The 120 year period mentioned in Genesis 6:3 was the length of the warning God gave mankind that the flood was coming to destroy them.
Had 120 years been the God ordained lifespan of mankind, then Moses, who wrote Psalm 90, could not have said, “The length of our days is seventy years – or eighty if we have the strength” (Psalm 90:10), and Isaiah could not have said that seventy years is a king’s lifespan (Isaiah 23:15). These are the only places I’m aware of in the Bible where an average human lifespan is measured.