n a sense, there are only 2 kinds of people on this planet: fools and followers; fools who reject God, and followers who receive Him... and more importantly who are received by Him. Now, before we rise up in pride and look with disdain upon the fools, we should keep reading. According to verses 2 & 3, all of the "children of men" are naturally ignorant, universally wayward, morally dirty and volitionally evil. WE are corrupt, and all of our deeds are abominable in God's eyes (Psalm 14:1& Isaiah 64:6).
But wait, David does introduce another category of people in this Psalm. He calls them "my people" in verse 4. He calls them "the generation of the righteous" in verse 5. He calls them "the poor" in verse 6. He calls them "His people" in verse 7... that is, God's people. Obviously, some transformation had to have occurred to these people to move them from the category known as the "foolish children of men" to a new group known as the "righteous children of God" - right? Of course! God had to have gone seeking after these fools and He had to have persuaded them to relinquish their foolishness and to trust in Him; to believe in Him; to make Him their refuge (Psalm 14:6).
Still, there was obviously more that David anticipated from God in addition to the enlightenment of the elect and their (I should say, our) adoption into God's family. David was looking forward to deliverance. He was looking forward to the defeat of the fools. Why? Because, the fools of this world outnumber the wise by far. Unbelievers outnumber believers. Rejecters exceed receivers. And, the god of this world has lifted many of his faithless children to places of prominence and power.