The Genesis Flood is an abiding warning of the wrath of God.  It is an abiding warning that God will not always stay his hand from judgement.  Yes, God will not destroy the world again by a great flood.  He will, however, end this age by defeating all of those who are in active opposition to Him, and bring glory to his Name.  Please remember that judgement upon this age will be because people will have trodden underfoot the Bood of the Living and Resurrected Jesus. Now is the accepted time, now is the Day of Salvation.