Dispensationalists see that God has worked with different people in different times in different manners. Usually, seven dispensations are identified: Innocence, Conscience, Government, Promise, Law, Grace, and Millennial Kingdom. Each dispensation reveals a six-fold pattern involving the stewards of the dispensation, their responsibility, a specific period of time, a failure, the resulting judgment, and God’s grace.
The second dispensation is that of Conscience—Genesis 3:23 to 8:19.
Stewards: Cain and Seth and their families The Period: From man’s expulsion from the Garden of Eden until the Flood, a period of about 1,656 years Responsibility: To do good and offer blood sacrifices (Genesis 3:7, 22; 4:4) Failure: Wickedness (Genesis 6:5–6, 11, 12) Judgment: The worldwide Flood (Genesis 6:7, 13; 7:11–14) Grace: Noah and his family are saved (Genesis 6:8–9; 7:1; 8:1)
During the dispensation of Conscience, mankind only became worse and worse. Guided by conscience, man was supposed to choose to do good and approach God by means of a blood sacrifice (Genesis 4:4). It was during this time that the first death occurred, when Cain slew his brother Abel (Genesis 4:8). God had accepted Abel’s animal sacrifice but not Cain’s grain sacrifice. Before the murder, God warned Cain of impending sin and told him that he could still choose to do well (Genesis 4:6–7). Cain had the opportunity to bring a proper sacrifice, after he saw what pleased God. But Cain let jealousy cloud his eyes. Cain demanded that God be pleased with his own efforts and refused to follow God’s plan. This kind of thinking still plagues mankind today, as people attempt to approach God on their own terms rather than on God’s terms.
Mankind violated his conscience and failed in his responsibility to choose to do right. Apparently, God wanted man to discover that he could not let his conscience be his only guide. Conscience proved to be a very poor guide, indeed. Out of all that lived in this dispensation, only Abel, Enoch, and Noah were called righteous (Hebrews 11:2–7; Genesis 5:22–24; 6:8–9). Genesis 6:5 states, “The Lord saw how great man’s wickedness on the earth had become, and that every inclination of the thoughts of his heart was only evil all the time.” The Lord’s solution was to destroy man from the face of the earth, along with all land-dwelling animals (verse 7). “But Noah found favor [grace] in the eyes of the LORD” (verse 8).
Noah warned his contemporaries for 120 years as he built the ark and as the LORD showed His great patience. God as the righteous Judge must deal with sin, and judgment was often quick and severe in the Old Testament. His judgment then—and His grace within that judgment—should inform us today. “For if God … did not spare the ancient world, but preserved Noah, a preacher of righteousness, with seven others, when He brought a flood upon the world of the ungodly … then the Lord knows how to rescue godly men from trials and to hold the unrighteous for the day of judgment, while continuing their punishment” (2 Peter 2:4, 9). The heathen today are under the same responsibility as mankind was from the Fall to the Flood, with their “conscience bearing witness” (Romans 2:15).
God extended grace to Noah and his family and gave instructions to build the ark and established His covenant with them (Genesis 6:14–22). God saved eight people and brought them forth into a new dispensation (Genesis 7:1; 8:1; Hebrews 11:7). The apostle Peter uses God’s grace to Noah as an illustration of God’s grace today to us who are saved by faith. Just as Noah and his family were “brought safely through the water,” we are saved by the baptism of the Holy Spirit—“not the removal of dirt from the flesh, but an appeal to God for a good conscience—through the resurrection of Jesus Christ” (1 Peter 3:19–21).
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.