Heb 11:1, 7 Now faith is the substance of things hoped for, the evidence of things not seen.
Many men and women spoken of in the Old Testament had nothing but promises of God to rest on. There was no visible evidence of these promises ever being fulfilled, yet they regulated the whole course of their lives toward their fulfilment.
Noah was one of them who lived according to the conviction of things not seen. Genesis 6:1-7 is the key text that Hebrews 11:7 points us to. It was a time that God had purposed to destroy life on earth by means of a flood on account of the wickedness of humanity. During these dark times emerged a man who found favor in the sight of God, namely Noah. He was a righteous and blameless man and his favor with God preserved him and his family. He was commanded to build an ark for them as well as for representatives of the animal kingdom as a refuge from the impending floodwaters.
So, Noah regulated the whole course of his life toward that promise. This was no small undertaking. Noah had to collect and shape the materials to build this enormous vessel. More significantly, the earth had never experienced a deluge like the one God warned Noah about, let alone the experience of rains; for the earth was watered by a mist (Gen. 2:6). Therefore, Noah had no other reason to think that a flood would come except by the promise of God. That was sufficient for him because he understood the character of God and was persuaded that what God promised, He would fulfill (Rom. 4:21).
By his faith, which was manifested in the construction of the ark, “he condemned the world and became heir of righteousness which is according to faith” (Heb. 11:7).
The people of Noah’s day did not trust God as Noah did. The majority of the people in our day do not trust God as we do. But while our faith condemns those around us, we must share the hope of the gospel by informing them that they too can escape the wrath of God as we have, by putting their faith in Jesus Christ and believing His promises.