And God saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually. (Gen 6:5)
And the Lord smelled a sweet savour; and the Lord said in his heart, I will not again curse the ground any more for man's sake; for the imagination of man's heart is evil from his youth; neither will I again smite any more every thing living, as I have done. (Gen 8:21)
These texts, set before and after the flood, are often used by Calvinists to support the doctrine of Total Depravity (or, as R.C. Sproul preferred calling it, “Radical Depravity”). Notwithstanding, Reformed apologists are guilty of absolutizing passages in this instance, as even before and after such texts, people are said to be righteous “in the eyes” of the Lord:
But Noah found grace in the eyes of the Lord. These are the generations of Noah: Noah was a just man and perfect in his generations, and Noah walked with God. (Gen 6:8-9)
And the Lord said unto Noah, Come thou and all thy house into the ark; for thee have I seen righteous before me in this generation. (Gen 7:1)
Such texts, which are also set within the flood narrative, shows that the text is not teaching the concept of Total Depravity—instead, the author is engaging in hyperbole when speaking of the fallen nature of man, a common practice one finds within the pages of Semitic literature.
For more, see, for e.g.: