Again, the years were certainly literal because there is nothing in the context of Genesis to indicate that the writer was speaking figuratively. And, since Moses was writing (Luke 24:44), he wrote with the same years in mind that were taking place in his day (he lived to 120 years).
The question of why people lived so long before the flood can only be answered by gathering the facts we know from the Bible and then theorizing the most logical explanation. Consider the following:
- II Peter 3:3-7 tells us that there was a different “world” (KOSMOS — order or arrangement of the world) before the flood and that this old world perished. Therefore, we must go to Genesis and find out how the old world was different.
- Genesis 1:6-7 tells us that there was a large body of water (evidently in vapor form) that God placed above the atmosphere. There is no such thing in our atmosphere today. This being so, Henry Morris of the Institute For Creation Research explains that such a body of water would have blocked out most incoming solar radiation along with increasing atmospheric pressure which would have dramatically contributed to human and animal health and longevity.
- This would explain why there was no rain in those days and no rainbow (Genesis 2:5). This amount of water in the atmosphere would have created uniform temperatures over the whole world with no polar ice caps and therefore no winds and no storms.
- This would also explain some of the unusual geologic discoveries. Even evolutionary scientist admit that at one time the earth was much warmer than it is now. Elephant ivory has been mined out of the ice of Siberia for over 200 years and the supply seems inexhaustible. An estimated 5 million African mammoths are buried in the ice along the coasts of Alaska and Siberia. Elephants have been found quick-frozen, with food half-chewed and half-digested. Evidence of tropical jungles have been uncovered where year-round ice packs exist.
- This large body of water in the atmosphere would also later be used by God to flood the world. Remember, it rained for forty days and nights covering the earth over twenty-two feet above the highest mountains. Such would be impossible today since all the water in the atmosphere would only cover the earth to about one inch.