Genesis 5:12

And Cainan lived seventy years, and begat Mahalaleel:

Cainan at seventy years fathered Mahalaleel as one link in the godly line from Adam through Seth to Enoch and Noah. He belongs to the nine generations before the Flood who lived nearly a thousand years, his own total reaching nine hundred and ten years in a time of remarkable health with no sickness and feebleness as known now. Because those long lives overlapped for hundreds of years, what God taught Adam was handed directly from generation to generation by men of strong memory without books, from Adam to Methuselah to Shem to Abraham and Isaac to Jacob. Though that long-lived race retained great vigor, rare powers to plan and execute, and the continual witness of righteous men, they gave loose rein to iniquity and despised the truth until the Lord destroyed them by the Flood.

Long Life Before Flood

Genesis 5:12 belongs to the nine generations before the Flood whose average age was 912 years, marking the starting point of a steady decrease to an average of 332 years in the nine generations after the Flood, to seventy years in Moses' time, and to about thirty-five years at present. The genealogies show this decline in human longevity from the pre-Flood average to the post-Flood average.

The patriarchs from Adam to Noah, with few exceptions, lived nearly a thousand years, in contrast to the steadily shortening human lifespan afterward. This record of long lives shows how much longer people lived in the early generations than they do now. The average human life span decreased after that early period.

The sacred record from Adam to Noah covers more than sixteen hundred years when vegetables, fruits, and grains were the diet of man. Cainan's full total was nine hundred and ten years and its record ends in simple death, showing a time of remarkably good health lived in full enjoyment for nearly a thousand years until the weary springs of life stood still. There is no mention of sickness and death of children, feebleness in youth or middle age, fevers, dyspepsia, gout, consumption, breakdown of organs, long-drawn sufferings, or agonies in death.

The protracted lives of the antediluvians were lengthened by the life-giving power of the tree of life transmitted from Adam and Eve. That tree possessed power to perpetuate life so that as long as they ate of it they could not die.

The race was created with ten times more vital force than it now possesses, which kept its violations of the laws of health and life from extinguishing it. The lifespan tapered to between one and two hundred years at the time of the Egyptian vassalage, to threescore years and ten at the time of David about halfway from Adam to the present, and to an average of thirty years in Europe and the United States now and twenty years in great cities, because violation of physical law cut human years to contemptible brevity.

Humanity originally retained great vitality for many centuries, and the shortening of life after Noah came through corrupt appetites and continued violations of the laws of life. The generations before Noah lived nearly a thousand years, and their long lives contrast with that later shortening.

Since the days of Noah disease has afflicted people with all manner of diseases in every town, city, and village until they were brought to Christ to be healed, and has steadily increased through successive generations with mortality increased to a fearful extent. This stands in contrast to the different condition of life during the first two thousand years and to the suffering and mortality prevalent in the present generation.

Knowledge Preserved and Rejected

For hundreds of years seven generations were alive on the earth at the same time, because the first generations lived hundreds of years side by side. This overlapping gave the men of that olden time far greater advantages for merely human knowledge than modern men have. Adam, formed in God's image and instructed by the Creator in all wisdom pertaining to the material world and in the history of creation, lived among them for hundreds of years and imparted to his descendants what he had learned and what he himself had witnessed through nine centuries. Without books or written records, men of great physical and mental vigor had strong memories able to grasp and retain what was communicated to them and to transmit it unimpaired to their posterity, while contemporaneous generations consulted together and each profited by the knowledge and experience of all.

Cainan's generation is one link in the genealogy showing how directly the knowledge of all that God taught Adam was communicated to his descendants. The long-lived line carried it from Adam to Methuselah, from Methuselah to Shem the son of Noah, from Shem to Abraham and Isaac, and from Abraham and Isaac to Jacob the father of the tribes of Israel. The overlapping lifetimes prove the shortness of the chain: Adam lived till Methuselah was 243 years old, Methuselah lived till Shem was 98, Shem lived 150 years after the birth of Abraham and 50 years after the birth of Isaac, Abraham lived till Jacob and Esau were 15 years old, and Isaac till they were 120. Cainan stands as one link in the godly line from Adam through Seth to Mahalaleel, Enoch and Noah, through which the truth about God was handed down by human lips from one generation to another. Daniel and his three companions were taught the history of Abel, Seth, Enoch and Noah and cherished it, so that the image of God was engraved upon their hearts and held them true in Babylon.

In Noah's day the human race still retained much of its early vigor, only a few generations after Adam had access to the tree that prolongs life, and man's existence was still measured by centuries. That long-lived people had rare powers to plan and execute, including many giants of great stature and strength, renowned for wisdom and skillful in devising cunning and wonderful works. Had they devoted themselves to God's service they would have made their Creator's name a praise in the earth and answered the purpose for which life was given to them, but they gave loose rein to iniquity, and their guilt was in proportion to their skill and mental ability. During that time righteous men including Seth, Enoch, Noah, Methuselah and others presented the truth and kept the knowledge of God continually before the world. The people despised the truth as people despise the truth today, the imaginations of their hearts was evil and only evil continually, and secret societies were formed to work in the darkness to do violence, until the Lord destroyed that long-lived race by a flood.