Even after Adam and Eve were driven out of the Garden of Eden by disobedience, people continued to sin.
The early part of Genesis 6 said that the sins of men were full of the world, so the heart of the Lord was filled with pain.
The number of people had increased as God blessed, but they married any of them they chose by judging their appearance, not their faith in God.
“It means that people only pursued the lust of the flesh, rather than following godliness and holiness.”
Seeing that all the plans and thoughts of man were wicked, the Lord set a plan to wipe away humankind, whom He had created. Then, leaving only Noah and his family, who found favor in the eyes of the Lord, He swept away all from the face of the earth as His plan.