Genesis 6:5 gives the reason clearly:
“Then the Lord saw that the wickedness of man was great in the earth, and that every intent of the thoughts of his heart was only evil continually.”
Humanity had reached a state of complete moral corruption. Sin was not occasional; it dominated every thought and intention of the heart. The earth had become filled with violence (Genesis 6:11), and the corruption spread so deeply that even creation itself was defiled. This rebellion was compounded by the actions of fallen angels taking human wives, producing the Nephilim, which further perverted God’s design.
God’s holiness cannot overlook sin. Genesis 6:6–7 says:
“And the Lord was sorry that He had made man on the earth, and He was grieved in His heart. So the Lord said, ‘I will destroy man whom I have created from the face of the earth… for I am sorry that I have made them.’”
This does not mean God made a mistake, but that human sin brought grief to His heart and demanded judgment. The flood was a global act of cleansing to stop the spread of evil and demonstrate that God is just. Yet even in judgment, grace prevailed. Genesis 6:8 declares:
“But Noah found grace in the eyes of the Lord.”
God preserved Noah and his family as a righteous remnant through whom His redemptive plan would continue. The flood stands as a solemn warning that God judges sin but also points to His mercy, ultimately fulfilled in Christ. Just as the ark was the only refuge from God’s wrath then, Jesus is the only refuge for sinners today (1 Peter 3:20–21).
