The Torah calls Noah "a righteous man, perfect in his generations." Targum Pseudo-Jonathan on (Genesis 6:9) tightens the description: "Noah was a just man, complete in good works in his generation, and in the fear of the Lord walked Noah."

Two qualifications. Noah's completeness was in his generation — meaning, perhaps, that he was righteous compared to the people around him. This is the famous rabbinic debate (Sanhedrin 108a): was Noah righteous in any generation, or only relative to a corrupt one? The Targumist leans toward "his generation," giving Noah real but qualified praise.

And the second qualifier: Noah walked in yirat Hashem, the fear of the Lord. Not in love, like Abraham will later walk. Fear. It is a lower rung of service, but it is enough. Noah feared the consequences, kept the commandments he had been given, and built an ark while his neighbors mocked. Sometimes fear is what carries you through a flood.