Psalm 14 addresses the topic of unbelief. It says that a person who is convinced within themselves that there is no God is a fool. Verse 1 goes on to say that humankind as a whole has become corrupt and constantly does wrong things.
Verses 2-3 show God looking down on earth and observing what everyone does, hoping to see faithful people who do what's right. Unfortunately, earth is full of people who have degraded their own selves. The speaker repeats that "there is none that doeth good, no, not one".
Verses 4-6 talk about the evil people as if they were rabid consumers, devouring the poor without a second thought about God, who is watching them. But eventually the wicked people experience fear because their behavior makes them the enemies of God, who is refuge for the righteous and the poor. The speaker concludes by hoping for the deliverance of Israel, which may refer to the Babylonian captivity or to numerous other times that Israel was oppressed.
1The fool hath said in his heart, There is no God. They are corrupt, they have done abominable works, there is none that doeth good.
2 The Lord looked down from heaven upon the children of men, to see if there were any that did understand, and seek God.
3 They are all gone aside, they are all together become filthy: there is none that doeth good, no, not one.
4 Have all the workers of iniquity no knowledge? who eat up my people as they eat bread, and call not upon the Lord.
5 There were they in great fear: for God is in the generation of the righteous.
6 Ye have shamed the counsel of the poor, because the Lord is his refuge.
7 Oh that the salvation of Israel were come out of Zion! when the Lord bringeth back the captivity of his people, Jacob shall rejoice, and Israel shall be glad.