When they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. Romans 1:21.
Notwithstanding the wickedness of the antediluvian world, that age was not, as has often been supposed, an era of ignorance and barbarism. The people were granted the opportunity of reaching a high standard of moral and intellectual attainment. They possessed great physical and mental strength, and their advantages for acquiring both religious and scientific knowledge were unrivaled. It is a mistake to suppose that because they lived to a great age their minds matured late; their mental powers were early developed, and those who cherished the fear of God and lived in harmony with His will continued to increase in knowledge and wisdom throughout their life.... As the years of human beings have decreased, and their physical strength has diminished, so their mental capacities have lessened....
The antediluvians were without books, they had no written records; but with their great physical and mental vigor, they had strong memories, able to grasp and to retain that which was communicated to them, and in turn to transmit it unimpaired to their posterity.... Far from being an era of religious darkness, that was an age of great light. All the world had opportunity to receive instruction from Adam....
Skepticism could not deny the existence of Eden while it stood just in sight, its entrance barred by watching angels. The order of creation, the object of the garden, the history of its two trees so closely connected with human destiny, were undisputed facts. And the existence and supreme authority of God, the obligation of His law, were truths that people were slow to question while Adam was among them.
Notwithstanding the prevailing iniquity, there was a line of holy men and women who, elevated and ennobled by communion with God, lived as in the companionship of heaven. They were people of massive intellect, of wonderful attainments. They had a great and holy mission—to develop a character of righteousness, to teach a lesson of godliness not only to the people of their time but for future generations. Only a few of the most prominent are mentioned in the Scriptures, but all through the ages God had faithful witnesses, truehearted worshipers.—Patriarchs and Prophets, 82-84.
From Christ Triumphant - Page 40
Christ Triumphant