Q: Why is general revelation insufficient for man's needs?
A: General revelation is able to point us to the fact that there is a God, but lacks the ability to communicate to us what the Lord requires of us. Things such as the knowledge of sin, salvation, repentance, the Gospel; these things can only be known through specific or special revelation as God reveals them to us. In short, within general revelation we may come to know that God exists, but it is in special revelation that we discover what the Lord requires, the depth of our sins, and how God reconciles us to himself (Romans 1:19-23, 3:9-26).
Q: Is it theologically plausible to argue that there are no real atheists? If so, on what grounds?
A: We would have to say, yes, based on the evidence of Scripture given in Romans 1:21-25:
For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things. Therefore God gave them up in the lusts of their hearts to impurity, to the dishonoring of their bodies among themselves, because they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever! Amen.
Therefore, the argument can be soundly made that Atheism is really just a delusion of a darkened mind that is bent toward idolatry. They may say that they believe in no god, but in fact are gods unto themselves, or they craft one of their choosing.
“Atheism is rather in the lip than in the heart of man.” - Francis Bacon
Hit me up if you have any discussion, questions, or comments.
Soli Deo Gloria,