Genesis 5

The first genealogy in Scripture gives us a look into the antediluvian (pre-flood) period of history. It traces the generations from Adam to Noah and his sons, and the ages of the men in the account stand out.

Let’s skip ahead to the next chapter for a moment:

“My Spirit shall not strive with man forever because he indeed is flesh; nevertheless his days shall be 120 years.”
-Genesis 6:3 (LSB)

There have been two primary interpretations to this phrase.

One is that God is saying that the flood will come relatively soon, in 120 years. In this way, He will not strive with men in this current state forever, but rather put an end to “all flesh” (6:13). This is almost certainly the direct meaning of this text, considering the immediate context of the flood and the ensuing timeline.

Other have interpreted this as the years of man will be limited to 120 years, meaning that their lifespans going forward (after the flood) will be reduced to “one hundred” (singular) and “twenties” (plural). This is interesting for two reasons:

1. The wording “...his days shall be 120 years” sounds very much like lifespans (going forward) will be limited in this way, as a plain reading of the text.
2. There seems to be a progression in the post-flood era of lifespans eventually reducing to the decade of 120 years of life (a reality that seems to continue to this day). This reduction was not immediate, but gradual, evidenced by the account of Shem’s descendents in Genesis 11 and beyond: Arpachshad (438), Eber (433), Peleg (464), Reu (239), Serug (230), Nahor (148), Terah (205), Abraham (175), Isaac (180), Jacob (147), Levi (137),  Kohath (133), Amram (137), Moses (120).

Whether or not both realities are meant in the text (that God gave humanity 120 years before he would flood the earth and also that God would begin reducing man’s lifespan to 120 years), it does seem that both became realities, and that the flood was the point of reference for both.

There are many understandable natural reasons as to why men lived over 900 years before the flood (Noah, 950), such as:

• The gradual effects of death on bodies that originally had the potential to live forever before sin brought death.
• The different atmosphere and climate before the canopy of water brought rain for perhaps the first time.
• The lack of widespread disease or developed conditions that most die from today (heart disease, cancers, etc.).
• Exclusive vegetarian diet before Noah and his sons began to eat animals (Genesis 9:3).

Beyond these, there could also be some intentional reasons for God to purpose long lives for the antediluvian patriarchs, like to populate the earth (6:1) and live long enough to build cities (4:17) and develop music (4:21) and tools (4:22), among other things.

But as we will see, all of those purposes were overwhelmingly affected by our sin, and God would soon bring judgment.