Genesis 4:17
And Cain knew his wife; and she conceived, and bare Enoch: and he builded a city, and called the name of the city, after the name of his son, Enoch. And Cain knew his wife; and she conceived, and bare Enoch: and he builded a city, and called the name of the city, after the name of his son, Enoch.
The fourth chapter of Genesis is to be read carefully, for it shows departure from God's plain commands that filled the world with transgression and sin and led God in the chapters that follow to destroy the world. After receiving God's curse, Cain withdrew from his father's household and went out from the presence of the Lord, casting away the promise of restored Eden to seek possessions and enjoyment on the earth under the curse of sin. His family line began after God in mercy spared his life, though his murder merited death, in order to grant him opportunity for repentance. He lived only to harden his heart and encourage rebellion against divine authority, becoming the head of a line of bold, abandoned sinners.
He built a city and called the name of the city after the name of his son, Enoch. Before building the city he had chosen to be a tiller of the soil, and Enoch was his eldest son. His building a city illustrates departure from God's appointed way of life and principles, as those who turned from God gathered in cities where splendor, luxury, and vice became sources of pride and harm. By this act he became the head of the great class of men who worship the god of this world, distinguished in mere earthly and material progress yet regardless of God and in opposition to His purposes for man.
Led on by Satan, Cain became a tempter to others, and his example and influence exerted a demoralizing power until the earth became corrupt and filled with violence so as to call for its destruction. Fifteen centuries after the sentence on Cain, the fruition of his influence and example was witnessed in crime and pollution flooding the earth. Sparing the first murderer set before the whole universe a lesson bearing on the great controversy, for the dark history of Cain and his descendants illustrates what would result from permitting the sinner to live on forever in rebellion against God, showing that God's forbearance only rendered the wicked more bold and defiant. It was thereby made manifest that the sentence of death pronounced on the fallen race for transgression of God's law is both just and merciful, for the longer men live in sin the more abandoned they become, and the divine sentence cutting short a career of unbridled iniquity and freeing the world from hardened rebels is a blessing rather than a curse. The verse belongs to the account of Cain's descendants, from whom Enoch separated because of their growing wickedness and lack of reverence for God.