Psalms 14:1

The fool hath said in his heart, There is no God. They are corrupt, they have done abominable works, there is none that doeth good.

The fool denies God, which is sheer folly, and that denial is joined to corruption and abominable works, with none doing good.
This denial is said in the heart and is largely practical, living as if there is no God, no heaven, and no future life, treating possessions as one's own and planning for self alone, even wishing Him away to escape His witness and accountability.
It persists despite the plain revelation of God's power and glory in creation, which needs no proof from human reasoning, and it is foolish because even the mightiest minds cannot comprehend Him, who reveals Himself only veiled in mystery with ways past finding out.
Exalting human science above God leads step by step into this denial, treating learned opinion as infallible and judging Scripture by science until the anchor is gone and doubters drift into skepticism and beat upon the rocks of infidelity.
The result is corruption seen in history, from those before the flood and idolatrous nations who misused God's gifts for idolatry, to France's public renunciation followed by degrading idolatry, bringing intemperance, crime, and suffering that denial cannot restrain or heal as trust in God can.

The Fool's Denial of God

To deny God is folly, and that folly is joined with corruption and evil conduct. The public renunciation of the living God in France during the Revolution showed this folly, for rejection was followed by degrading idolatry in worship of the Goddess of Reason. Such denial cannot restrain crime, awaken the higher powers of humanity, purify the soul, or give hope beyond death, leaving its professors in despair in contrast with the confidence of those who trust in God and look forward to life beyond the grave. The infidelity spreading as people and nations forsake God is this same mark of folly, associated with corruption and evil.

The denial is practical atheism, living as if there is no God, no heaven, and no future life. It treats everything possessed as one's own and acts as though nothing is owed to God or to other people. It is living and planning for self alone, without regard for heaven. The foolish rich man of the parable is the picture of it, whose aims rise no higher than the beasts that perish.

The denial is said in the heart, putting God out of mind and heart even when existence cannot be denied. It includes wishing there were no God to witness deeds and hold people accountable. It persists although God's power and glory are plainly revealed in creation, whose testimony needs no proof from human reasoning, while weak suppositions only obscure the truth. Those who look at His works and still deny His existence show lack of true knowledge because Christ is hidden from them, and they are not to be trusted as sources of knowledge for what they ought to know.

The denial is foolish because even the mightiest human minds cannot comprehend God. He reveals Himself only by veiling Himself in mystery, His ways are past finding out, and men must keep searching and learning with an infinity always beyond. If men could fully understand His purposes, wisdom, love, and character, He would no longer stand supreme as an infinite being to be believed in and trusted with the interests of the soul. Exalting human science above God leads step by step to this denial, treating the opinions of learned men as infallible and teaching the deductions of science as truths that cannot be controverted. Such men judge the word of God by that standard and pronounce it wanting, their research becoming a snare that clouds the mind and drifts them into skepticism through consciousness of power with only a smattering of knowledge, refusing to look to the Source of all wisdom, exalting human wisdom in opposition to the wisdom of God, and daring to enter into controversy with Him. Doubting Bible history and the reliability of the records of the Old and New Testaments because Creator and works cannot be explained by natural laws leads a step farther to doubting the existence of God, and having let go their anchor such doubters are left to beat upon the rocks of infidelity.

Corruption and Historical Manifestations

Denial of God is joined with corruption, abominable works and evil conduct, with none doing good, marking the character to be shunned. This unbelief turns from the Creator who has generously provided for human benefit to worship what human hands have made, misusing His gifts and sinking into increasing debasement. Such a self-centered life lives and plans for self alone, with aims no higher than the beasts that perish. The same corruption exposes a false form of Christianity which, despite abundant light and evidence, has lost loving communion with God, feeds on strife and falsehood instead of Christ and the gospel, holds false ideas about God and Christ, departs from Scripture, distorts gospel truth, and shows no genuine Christian holiness in word and action.

The corrupt and ungodly condition of the world and the church, without righteousness or fear of God, comes from making God's law void by breaking it and teaching others to disregard the light of truth. Before the flood this denial refused to acknowledge God as Creator of heaven and earth and gave Him no grateful thanks for gold, silver, precious stones, choice wood, and every provision for building and beautifying houses and lands. Instead men gloried in and worshiped works of their own hands, forming images and teaching their children to regard hand-made pieces as gods and to worship them. They misused what God had placed on earth for man's benefit by preparing beautiful walks overhung with fruit trees of every kind, placing idols under majestic lovely trees with wide-spread branches green from year's beginning to its close, with whole groves dedicated to idol gods and made attractive for idolatrous worship, and by these wicked deeds provoked God.

Idolatrous nations deny God by conduct in refusing to honor and thank the Creator, corrupting His gifts to idolatry, worshiping images made with their own hands, teaching others to trust them, scorning God and His people because their works are righteous, and seducing Israel into idolatry. God bears with them until their iniquity is full, then may bring swift destruction upon them and use His people to punish nations that vexed and seduced them. France's public renunciation of the living God in the Revolution fulfilled the fool's denial, and its rejection was followed by degrading idolatry in the worship of the Goddess of Reason.

The infidelity spreading as people and nations forsake God is folly associated with corruption and evil. It brings intemperance, crime, degradation and widespread suffering that could have been prevented if earlier generations had been taught to fear, love and obey God. This denial cannot restrain crime, awaken humanity's higher powers, purify the soul, or give hope beyond death. Hence the despair of professed atheists stands in contrast to the confidence of those who trust in God and look forward to life beyond the grave.