The ages and the way in which this genealogy is presented has always fascinated me. I don’t believe that anything God includes in His Word is wasted, so I’ve researched and studied to try to understand the significance and the meaning behind the ages, which obviously strike us today as unusual.
Several explanations are plausible. One is that when Genesis 1:6-8 describes the waters below and the waters above, the waters above represented a vapor canopy that filtered the harmful ultraviolet rays of the sun, allowing a sort of greenhouse that protected creation and allowed for human lives to be much longer.
The cumulative effects of mutations to DNA over generations make us less and less resilient, more prone to the effects of sin, namely death and disease, cutting our lives short from God’s original design.
The earth’s rotation around the sun has expanded in tiny increments over thousands of years, meaning that a “year” at the time of Adam and Eve was much shorter than it is today. In fact, according to Science Alert, a day was once only 18 hours. https://www.sciencealert.com/earth-days-getting-longer-lunar-retreat-astrochronology
I’m not a scientist, and even those who are constantly re-evaluate and revise their theories. But there are interesting and plausible explanations for the years in this account even when they seem impossible in our current experience.
But I also researched and discovered something interesting about the way the dates line up. If you create a timeline and place the dates, and the lengths of life on it, you’ll find that the account of the flood occurs in year 1656 following Adam’s creation. Each of the lives mentioned begins, and ends, prior to that year, except for Noah, of course. Sadly, Methusaleh, Noah’s grandfather, the man who lived the longest life recorded in the Bible at 969 years, died the same year as the flood.
For me, the accuracy of this detail in the accounts strengthens my faith in God’s Word. God doesn’t expect us to check our brains at the church door, but He does expect us to consider that where our understanding and His Word differ, perhaps we are the ones who are wrong. Faith includes trusting that God knows more than I will ever know.