Perhaps you are thinking of the time before the flood when God saw  the evilness of man. Genesis 6:5-8 (CSB), 5 “When the LORD saw that human wickedness was widespread on the earth and that every inclination of the human mind was nothing but evil all the time, 6 the LORD regretted that he had made man on the earth, and he was deeply grieved. 7 Then the LORD said, ‘I will wipe mankind, whom I created, off the face of the earth, together with the animals, creatures that crawl, and birds of the sky ?– ?for I regret that I made them.’” 

When God watches the pain and suffering people experience because of evilness, it deeply grieves Him. The scriptures show the depth of God’s sorrow when God says He will wipe mankind from the earth. But God did not act on His grief. He showed grace and saved Noah and his family.

God knows the end of a matter from its beginning. Isaiah 46:9-10 (CSB),  “Remember what happened long ago, for I am God, and there is no other; I am God, and no one is like me. I declare the end from the beginning, and from long ago what is not yet done, saying: my plan will take place, and I will do all my will.” So what is God’s plan for man?

When God made man in His own image, He gave man free-will. God wanted people to worship and love Him because it was their choice. God also foreknew that man would choose sin over righteousness. Thus, even before the world was created, God designed a plan. This plan would permit man to experience sin and then give man the opportunity to learn righteousness. Man would be redeemed “with the precious blood of Christ…He indeed was foreordained before the foundation of the world…” 1 Peter 1:19-20 (NKJV).

With God’s loving redemption plan in place, He would not destroy man. He would redeem us from sin and death. God’s plan will restore to mankind all that was lost in the Garden of Eden. Perfect health, peace between God and man and between men, justice for all, the earth yielding her increase. All those who choose to follow righteousness will have eternal life on Earth. Revelation 21:4-5 (NKJV), “And God will wipe away every tear from their eyes; there shall be no more death, nor sorrow, nor crying. There shall be no more pain, for the former things have passed away.” Then He who sat on the throne said, ‘Behold, I make all things new.’” 

The disobedient will die the second death and cease to exist. They will “not hurt nor destroy in all My holy mountain, For the earth shall be full of the knowledge of the LORD As the waters cover the sea.” Isaiah 11:9