† From Adam to Noah, the average life span was 912 years (not counting Enoch) (Gen 5:5-31; 9:28). From Shem to Abraham, the average was 317 years (Gen 11:10-31). Are there any good explanations to human longevity recorded in Genesis?
What are the normal explanations for the longevity of man in ancient times?
The longest living man was Methuselah who lived 969 years, about 8 times longer than the oldest human on record in the 20th century even though we now possess advanced technology to extend life.
 Legends: The record is fictional or legendary and does not reflect reality.
 Dynasties: The length indicates only the duration of his clan or family dynasties. BUT this cannot explain the case of Enoch.
 Shorter years: The ancient “Hebrew” year was shorter than a year of today. BUT if 8 pre-Flood years roughly equalled 1 year today, then Enoch and Mahalalel had their children at about age 8.
 Different Earth: The revolution period around the sun has slowed significantly. BUT growing food depended on the length of seasons.
 Symbolic: The numbers were only a symbol of long life, magnifying God’s blessing.
 Genetics: Human beings were genetically more pure in this early time period, so there was less diseases to shorten their life spans.
 Populate the Earth: God deliberately gave early people longer lives so that they had time to “fill the earth.”
The explanations are arranged in the order of the least likely (no.1) to the most likely (no.7).
What are the possible reasons to explain the shorter life span after the Flood?
 Disappearance of the canopy (a shield of water vapour):
Large amount of radiation can shorten human life spans. The canopy theory presumes that Gen 2:6 describes “streams” or “mist” coming out of the ground forming a shield of water vapour in the atmosphere cutting down various forms of life-shortening radiation from outer space. This canopy disappeared after the Flood.
However, there are 4 problems: [a] There is no evidence for such a canopy. [b] The canopy would either collapse or dissipate into outer space. [c] Such covering would set up a powerful greenhouse effect to vaporize all water. [d] The vapour canopy would not impede the hard cosmic rays.
 Radiation from radioisotopes from igneous rocks (e.g. uranium, radium, thorium):
It is possible that pre-Flood people lived far from igneous rocks. However, today, people who grow up and live all their lives in these areas do not have significantly longer life expectancy.
 Cosmic radiation:
In 1996, two astronomers found empirical evidence that most of the cosmic rays striking Earth come from a recent, nearby supernova called Vela, about 1300 light-years away. The time of the supernova is estimated to be 9000 BC to 35,000 BC. Gen 11 indicates that the change in life span dropped gradually. This may indicate the shortening of human life span as a result of increasing effects of cosmic radiation from Vela.
 Apoptosis (biochemically “programmed” cell death):
Recent research shows that our cells are designed to shut down after a certain number of cell regenerations. Because of this, no matter how healthy and safe a lifestyle a person leads, he or she will not live beyond about 120 years. This apoptosis may seem a curse but it is also a blessing in disguise because it limits the development and spread of cancers.
Who were the “sons of God” and “daughters of man” in Gen 6:2?
 Just another name for ordinary men and women. Difficulties:
o The event apparently resulted in God’s decision (punishment) in Gen 6:3. Ordinary marriages should not cause such a reaction from God.
o How would such marriages give birth to “mighty men of old” in Gen 6:4?
 Reference to the male descendants of Seth marrying the female descendants of Cain. Difficulties:
o OT reference of “sons of God” is restricted to the Israelites, never to the descendants of Seth.
o Would the marriages between believers and non-believers result in God’s wrath?
o Were there no intermarriages between the sons of Seth and the daughters of Cain before ch.6?
 Reference to human leaders marrying ordinary women. Difficulties:
o Why would these marriages give birth to mighty men of old? Counter explanations: [a] The people in Gen 6:4 were not the children from the marriages in Gen 6:2. These people simply existed in that time. [b] “Mighty men of old” and “men of renown” did not refer to giants but only to princes and warriors.
o Why would it lead to God’s destruction of mankind? Counter explanation: The sin is arrogance and polygamy (note the plural for daughters), corresponding to Lamech’s arrogance and polygamy.
 Reference to fallen angels marrying human females. Difficulties:
o If that was the sin of fallen angels, why did God destroy human beings? Counter explanations: [a] The women might be willing participants. [b] This is only one example of the numerous sins on Earth.
o Angels are not corporeal beings and are probably non-sexual. They do not possess any DNA for reproduction. Counter explanations: Fallen angels could possess human beings.
o If that happened before the Flood, what can stop them from not repeating it now? Counter explanations: When Jesus encountered evil spirits, they seemed to be afraid of being sent to the place of darkness and chains described as “the Abyss”. The threat of consignment to the Abyss for angels who cross a sexual boundary was instituted at or after David’s time.
Conclusion: Many commentators support the 2nd explanation while the 3rd explanation seems the best.
† We learn from the Bible about longevity:
o [a] The quality of life (how close you are with God) is a lot more important than quantity of life (how long you live). Enoch’s life span was much shorter than the other patriarchs of his time. But he walked with God for 300 years and became only 1 of 2 persons in history who avoided death.
o [b] From Enoch’s example, we understand that short life is not necessary bad. Dying young may be a tragedy for the person’s loved ones, but may be a blessing for the person who dies in Christ.
o [c] As saved people in Christ, we do not need to wish for eternal life; we have it already.
† The passage of Gen 6:1-4 is a difficult passage. Even after many centuries of looking for answers, we still cannot find sufficient information to draw firm conclusions. We should know that if the accurate exposition of this passage is necessary for our faith, then God would not allow this to happen. Therefore, we know that the interpretation of this passage has no crucial bearing on our relationship with God or on our confidence in the reliability of His Word.