All human beings have turned aside from the wise way of fearing the Lord (cf. Genesis 6:5-6; Genesis 11:1-9). 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. Romans 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 (righteousness) that only God can provide for us. [source][source][source]
Context Summary
Psalm 14:1-7 - The Bounty Of God And The Folly Of Men
The first of these psalms evidently dates from the Sauline persecutions, 1 Samuel 19:1. Four times the persecuted soul cries, How long! The psalm begins in deepest dejection, but clears as it proceeds. Prayer often proves to be the ladder from the deepest dungeon to the more radiant day. We find here depression, Psalms 13:1-2; supplication, Psalms 13:3-4; assurance, Psalms 13:5-6. Do not carry your anxieties in your heart. Remember that Christ is by your side, and leading you through all to the Kingdom. Faith begins praise for victory before the fight has reached its worst.
The creed, character, and doom of the atheist are set forth in the next psalm, and the psalm is so important as to demand repetition. See Psalms 53:1-6. The root of atheism is in the heart, Romans 1:21. Its effect on character, speech, and action is disastrous, and it ends in great fear, Psalms 14:5. The best answer to atheism is the light and liberty of the children of God, Psalms 14:7; Hebrews 9:28; 2 Thessalonians 1:6-10. [source]
Chapter Summary: Psalm 14
1David describes a natural man 4He convinces the wicked by the light of their conscience 7He glories in the salvation of God
What do the individual words in Psalms 14:3 mean?
Allthey have turned asidetogetherthey have become corrupt[There is] nonewho doesgoodNonotone