Question: “What does the Bible mean when it says “The fool says in his heart, ‘There is no God’”?”
Answer: Both Psalm 14:1 and Psalm 53:1 read, “The fool says in his heart, ‘There is no God.’” Some take these verses to indicate that atheists are stupid, i.e., lacking intelligence. However, that is not the meaning of the Hebrew word translated “fool.” In this text, the Hebrew word is nabal which refers more to a “moral fool,” e.g., someone without morals. The meaning of the text is not “unintelligent people do not believe in God.” Rather, the meaning of the text is “immoral people do not believe in God.”
Many atheists are very intelligent individuals. It is not intelligence, or a lack thereof, that leads a person to reject belief in God. It is a lack of morals that leads a person to reject belief in God. People do not reject the idea of there being a Creator Being. Rather, people reject the idea of there being a Creator Being who demands morality from His creation. In order to clear their consciences and relieve themselves of guilt, people reject the idea of God as the only source of absolute morality. Doing so allows atheists to live however they choose—as morally or immorally as they desire—with no feelings of guilt for their refusal to be accountable to God.
Several prominent atheists have admitted this. One famous atheist, when asked what he hopes to accomplish through atheism, declared that he wants “to drink as much alcohol and have sex with as many women as possible.” Belief in a divine Being is accompanied by a feeling of accountability and responsibility toward that Being. So, to escape from the condemnation of conscience, which itself was created by God, one must deny the existence of God in order to deny the moral pull of the conscience.
This is not to say that all atheists are immoral people. Many atheists live relatively moral lives. The point of “The fool says in his heart, ‘There is no God’” is that a lack of evidence of His existence is not the true reason people reject belief in God. People reject belief in God due to a desire to live free of the moral constraints He requires and to escape the guilt that accompanies the violation of those constraints. “The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, since what may be known about God is plain to them … men are without excuse … their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools … Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. They exchanged the truth of God for a lie” (Romans 1:18-25).
Recommended Resource: I Don’t Have Enough Faith to be an Atheist by Norm Geisler and Frank Turek.