He believed without seeing. Noah had no conception of the torrent of destruction that would descend on the world, but he believed in what God said even though he had never beheld it. In the same way the readers should look to the unseen and believe what God promised would be realised.
1 Through that faith he obeyed God.
7 By faith Noah, being warned by God concerning events as yet unseen, in reverent fear constructed an ark for the saving of his household. By this he condemned the world and became an heir of the righteousness that comes by faith.