Q. Did Old Testament characters really live as long as the Bible states, or are we to measure biblical years in different terms than our current method?
No, we are not to measure biblical years in different terms than our current method of 365 days to a year. Yes the Patriarchs of the Old Testament really did live as long as the Bible states. How do we explain this?
Some so called “scholars” claim that the ancient calendar made the year a month, or one lunar period. Others assert that a year equals one growing season of three or four months. One group says that a year in the bible was actually three months from Adam till Abraham, eight months till Joseph’s time, and twelve months thereafter. None of these “scholars” give any scriptural evidence for their preposterous conclusions.
Let me illustrate. If we accept the idea that one year actually equaled one month in our time, we have Enoch at five years old when his son Methuselah was born! The age of all the patriarch at the birth of their children would be equally preposterous.
This being true, how do we explain the long life-spans of the Patriarchs? One explanation might be the dramatically different world that the Patriarchs lived in. Before the flood the Bible indicates that there had been no rain. Many believe there was a “water-vapour” canopy surrounding the earth, giving greater protection from the sun’s radiation, and creating a sub-tropical environment all around the world. This would account for the fossil record which indicates sub-tropical vegetation all over the earth at some time in earth’s past. In such a moist atmosphere growth would have been greatly stimulated (for both man and animals), the oxygen content could have been much higher than present day conditions, man could have been stronger with greater endurance tending to longevity.
This all seems to explain why there is a steady progression of declining ages of men as their distance from the Creation increases. Adam lived 930 years, his son Seth lived 912 years. Lamech was his son, he lived 777 years. Noah was his son, he lived 950 years. Shem was his son, he lived 600 years. Shem’s son (Arphaxad) lived 438 years. Arphaxad’s son Salah lived 403 years. Jump a few generations to Abraham, he lived 175 years. Skip a few more generations to Moses, he lived 120 years. His age brings us down to the age some people live in our own time. There is a woman living in France today that is 126!
Why the decline in ages? Probably the change in the environment from the beginning to Moses day. There is no reason to believe that there should be a different way of counting Old Testament years.
From What do the Scriptures Say