14:1 A fool (Heb. nabal) is a person who does not take God into account as he goes about living and who is therefore morally insensitive (cf. 1 Sam. 25:25). He may or may not really be an atheist, but he lives as though there is no God. This conclusion leads him to disregard the revelations God has given of Himself attention to which are essential for wise living (cf. Prov. 1:7; Rom. 1:22). Instead he gives himself over to corrupt living and deeds that are abominable in the sight of God. Really, David observed, there is no one who does what is good in the sight of God on his own (unmoved and unaided by the Spirit of God).
14:2 God does indeed look down on people to assess our condition (cf. Gen. 11:1-9; 18:21). The arrogant materialist of verse 1 is only one example of humanity in general.
14:3 All human beings have turned aside from the wise way of fearing the Lord (cf. Gen. 6:5-6). The result is that they have become corrupt (Heb. alah, lit. sour, like milk) morally. Not one solitary individual does good in the sight of God on his own initiative and in his own strength (cf. Rom. 3:23). It is for this reason that no one can be acceptable to God on the merit of his own works. All need the goodness that only God can provide for us.