Genesis 4:18

And unto Enoch was born Irad: and Irad begat Mehujael: and Mehujael begat Methusael: and Methusael begat Lamech.

The verse records successive links in the genealogy headed by Cain, in which Enoch was Cain's eldest son, followed by Irad, who begat Mehujael, who begat Methusael, with Lamech as fifth in descent from Cain. The line began after Cain withdrew from his father's household under the curse, went out from the presence of the Lord, cast away the promise of the restored Eden, and sought possessions and enjoyment in the earth under the curse of sin. Cain first chose tilling the soil and then founded a city, which he named after his son Enoch. That genealogy stands at the head of the great class who worship the god of this world, bold, abandoned sinners distinguished in mere earthly and material progress but regardless of God and in opposition to His purposes for man.

Their city-building contrasts with the rural life and pastoral tent life of Abel continued by Seth's descendants, who held to God's principles as strangers and pilgrims on the earth seeking a better, heavenly country. Because of the growing wickedness and disregard for God among Cain's descendants, the righteous Enoch separated himself from them. Lamech at the end of the list added polygamy to the crime of murder which Cain began, boastfully defiant and acknowledging God only to draw from the avenging of Cain an assurance of his own safety.

Spared the death his crime merited and given opportunity for repentance, Cain only hardened his heart, encouraged rebellion against divine authority, and, led on by Satan, became a tempter whose demoralizing example and influence made the earth corrupt and filled with violence so as to call for its destruction. The fourth chapter is therefore to be read carefully because it tells the whole story, leading into the later account of God destroying the world because departure from His plain commands filled it with transgression and sin, with the fruition of Cain's influence appearing fifteen centuries after the sentence on Cain in crime and pollution flooding the earth. The dark history of Cain and his descendants illustrates what permitting the sinner to live on forever in rebellion against God would produce, presenting a lesson before the whole universe bearing on the great controversy. It makes manifest that the sentence of death on the fallen race for transgressing God's law was both just and merciful, since God's forbearance only rendered the wicked more bold and defiant and the longer men lived in sin the more abandoned they became, so the divine sentence cutting short unbridled iniquity and freeing the world from hardened rebels was a blessing rather than a curse.