Bible Gateway:
https://www.biblegateway.com/passage/?search=Psalm+14&version=AMP
Bible Hub Commentary Psalm 14:3
https://biblehub.com/commentaries/psalms/14-3.htm
Matthew Henry's Concise Commentary:
Let us lament the corruption of our nature, and see what need we have of the grace of God: let us not marvel that we are told we must be born again!

14:1-7 A description of the depravity of human nature, and the deplorable corruption of a great part of mankind. - The fool hath said in his heart, There is no God. The sinner here described is an atheist, one that saith there is no Judge or Governor of the world, no Providence ruling over the affairs of men. He says this in his heart. He cannot satisfy himself that there is none, but wishes there were none, and pleases himself that it is possible there may be none; he is willing to think there is none.