The Lord wiped out all life on earth—people, livestock, creatures that run along the ground, and birds. All were killed. The only ones left were Noah and those with him on the ark.
Noah trusted God, and was warned by him about things that had never happened before. Because Noah paid serious attention to what God said, he constructed an ark to save his family. By trusting God, Noah showed that the world was wrong, and received the reward of being set right by God.
that refused to believe, when God patiently waited in the time of Noah while the ark was being built. Only a few—in fact eight people—were saved “through water.”
God didn't spare the ancient world either, but he protected Noah who told people about the God who did right. He was one of the eight who were saved when God sent a flood upon a world of evil people.
As you can see, the Lord is able to rescue from their troubles those who respect him, and to keep the wicked until the day of judgment when their punishment is completed.