Hebrews 11: 7 NLT
“It was by faith that Noah built a large boat to save his family from the flood. He obeyed God, who warned him about things that had never happened before.”

What Noah did was act on blind faith. He had never seen a flood of this magnitude but he believed God and went to work. In the words of Mary, the mother of Jesus, in John 2:5 NASB, “Whatever He says to you, do it.”