There are three voices in this psalm, each followed by a comment: (a) the fool, v1; the Lord, vv2ff; and Israel, v7.  (NBC)

Psa 14:1 For the director of music. Of David. The fool says in his heart, “There is no God.” They are corrupt, their deeds are vile; there is no one who does good.

The fool says in his heart, “There is no God.” – ‘The atheism in question is more practical than theoretical, not so much denying God’s existence as his relevance.’ (NBC)

‘The “fool” in his heart denies the practical import of God’s existence. He shuts off the affairs of this world from divine intervention and denies any personal accountability to God for his actions (cf. 10:4; 73:11). Within the congregation he may mimic the sounds of faith, but his true self shows disregard for God, his commandments, and his people. He is characterized by an absence of concern or love for others, but he is occupied with himself.’ (EBC)

‘Not that he denies the existence of a supreme being that created the world, but his regarding the creatures, his government of the world, and consequently his reward of the righteous or punishments of the wicked.’ (Charnock, The Existence and Attributes of God)

The switch from the singular (‘the fool’) to the plural (‘they’) suggests that these practical atheists, if not actually in the majority, are certainly plentiful in number.

Note their moral (‘corrupt’), spiritual (‘corrupt’) and practical (they do not do good) character.

‘Every man, so long as he lieth unrenewed and unreconciled to God is nothing in effect but a madman.’ (Dickson)

Thomas Brooks: “He that doth not believe that there is a God, is more vile then a devil. To deny there is a God, is a sort of atheism that is not to be found in hell.”

‘No man says, “There is no God” but he whose interest it is there should be none.’ (Augustine)

‘Were all human beings suddenly to become blind, still the sun would shine by day and the stars by night, for these owe nothing to the millions who benefit from their light. So, were every man on earth to become atheist, it could not affect God in any way. He is what he is in himself without regard to any other. To believe in him adds nothing to his perfections; to doubt him takes nothing away.’ (A.W.Tozer, The Knowledge of the Holy, 40)

We believe that traditional dogmatic or authoritarian religions that place revelation, God, ritual, or creed above human needs and experience do a disservice to the human species.

Promises of immortal salvation or fear of eternal damnation are both illusory and harmful. They distract humans from present concerns, from self-actualization, and from rectifying social injustices.

We affirm that moral values derive their source from human experience. Ethics is autonomous and situational, needing no theological or ideological sanction. Ethics stem from human need and interest. To deny this distorts the whole basis of life. Reason and intelligence are the most effective instruments that humankind possesses. There is no substitute; neither faith nor passion suffices in itself.

No deity will save us; we must save ourselves. (Humanist Manifesto II, 1973)

‘Commenting that atheism “may be learned, taught and adapted, but it cannot be neutral”, the British preacher Robert Sheehan gives a simple illustration. A child visiting an art gallery would ask of an exhibit, “Who painted that?” On a visit to a science museum, the question would be: “Who invented that?” As Sheehan writes, “He is by nature a creationist. Paintings have painters, inventions have inventors. Which child (or adult) would naturally ask, “By what process did that painting (or invention) evalve by chance?” … Cross the road to a natural history museum and a child (and adult) would naturally respond in the same way. He would see in God’s handiwork God’s imprint. He would look for a creator…Atheism may be taught, but it is contrary to nature.”‘ (Blanchard, Does God Believe in Atheists? p490f)

‘He doth not form a syllogism, as Calvin speaks, that there is no God; he dares not openly publish it, though he dares secretly think it; he cannot rase out the thoughts of a deity, though he endeavours to blot those characters of God in his soul; he hath some doubts whether there be a God or no: he wishes there were not any, and sometimes hopes there is none at all; he could not so ascertain himself by convincing arguments to produce to the world, but he tampered with his own heart to bring it to that persuasion, and smothered in himself those notices of a deity, which is go plain against the light of nature that such a man may well be called a fool for it.’ (Charnock)

Psa 14:2 The LORD looks down from heaven on the sons of men to see if there are any who understand, any who seek God.

Psa 14:3 All have turned aside, they have together become corrupt; there is no one who does good, not even one.

The converse of ‘not seeking God’, v2, is deliberately ‘turning aside’.

There is no one who does good, not even one – ‘The apostle, in quoting part of this psalm (Rom 3:10, etc.) to prove that Jews and Gentiles are all under sin (v. 9) and that all the world is guilty before God (v. 19), leads us to understand it, in general, as a description of the depravity of human nature, the sinfulness of the sin we are conceived and born in, and the deplorable corruption of a great part of mankind, even of the world that lies in wickedness, 1 Jn 5:19.’ (MHC)

Psa 14:4 Will evildoers never learn– those who devour my people as men eat bread and who do not call on the LORD?

Psa 14:5 There they are, overwhelmed with dread, for God is present in the company of the righteous.

Psa 14:6 You evildoers frustrate the plans of the poor, but the LORD is their refuge.

Psa 14:7 Oh, that salvation for Israel would come out of Zion! When the LORD restores the fortunes of his people, let Jacob rejoice and Israel be glad!

When the Lord restores the fortunes of his people – ‘The phraseology “restore the fortunes” is characteristic of the prophets as they describe the era of restoration when Israel, restored to the land, will again enjoy the blessings of God (cf. Eze 16:53; Zep 2:7). After the Exile God demonstrated his faithfulness by his renewed blessings, by restoring Israel to the land, and by permitting his temple to be rebuilt. The psalmist anticipates an era when God will vindicate his people and deliver them from the fools who oppress them. In Jesus’ coming Jews and Gentiles are further assured of God’s concern, vindication, and presence with his people (cf. Rom 11).’ (EBC)