From what I recall (meaning that I heard him state it but do not know if he put it into writing), the Atheist activist Dan Barker claimed that God cannot be omniscient (all knowing) because God would not know if there is something He does not know.
As Donald Rumsfeld so famously or, infamously, put it:
There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don’t know. But there are also unknown unknowns. There are things we don’t know we don’t know.
Of course, by definition, the very concept of omniscience denotes that omniscience is just that; possessing all knowledge thus, making not know something simply incoherent. The concept itself refutes Barker’s supposed problem.
Christopher Hitchens stated:
Well it’s here that we find something very sinister about Monotheism and about religious practice in general. It is incipiently at least and I think often explicitly totalitarian, because I have no say in this. I am born under a celestial dictatorship which I could not have had any hand in choosing. I don’t put myself under its Government. I am told that it can watch me while I sleep. I’m told that it can convict me of, here’s the definition of totalitarianism, thought crime, for what I think I may be convicted and condemned.
—stated during the Christopher Hitchens and Alister McGrath debate, “Poison or Cure? Religious Belief in the Modern World”.
Note certain key terms: totalitarian, dictatorship, watch me. Firstly, even within an Atheistic universe, some of his concerns still apply since if the universe came into being when no one caused nothing to explode for no reason and made everything without reason and no meaning then; he had no say, he is born under a thermodynamic dictatorship which he could not have had any hand in choosing, he does not chose to put himself under its Government but is under it nevertheless, the laws of thermodynamics (such as entropy) act upon him even whilst he sleeps.
Secondly, as for issues of “thought crime” there are various directions to go with it.
1) There are perfectly legitimate thought crime related concepts such as degrees of murder with one being premeditated. If you planned it out, in your thoughts, ahead of time then the sentence is stiffer.
2) Atheist activist Sam Harris actually prescribes capital punishment for thought crime, “Some propositions are so dangerous that it may even be ethical to kill people for believing them” (The End of Faith, W. W. Norton & Company, 2005 AD, pp. 52-53).
3) In our modern era, we are told to not be concerned about omni-surveillance as long as we have nothing to hide (thank you NSA). It would appear that people do not like the idea of God’s omniscience because He would know their thoughts and motivation and not only the actions which result therefrom.
If God is then God would have to be a personal being. Some refer to the universe, energy, a force, etc. in anthropomorphic terms yet, that would be just that: humans taking it upon themselves to apply human attributes to something non-human.
Some also refer to the universe, energy, a force, etc. as gods since they can think of nothing higher. And indeed, if God is then God would, by definition, be the ultimate, highest, being. Moreover, by further definition there can only be one most high true living God as there can only be one ultimate being.
Also by definition, a personal being is one that has to possess the ability to judge; at this point, simply referring to making choices. We judge whether or not to get out of bed when the alarm sounds, what clothes to wear, what is right and wrong, etc.
By definition the ultimate being would be the ultimate judge and thus, would be qualified to ultimately judge; now referring to coming to certain determinations as to, for example, who is saved and who is condemned.
By further definition, in order to be the ultimate judge God would have to by omniscient. In this way, the ultimate judge judges in accordance to not only actions but the thoughts that motivated the actions.
This would make God the ultimately fair judge who takes every conceivable piece of evidence into consideration.
Therefore, God must be and is omniscient.
Here are some relevant texts:
Jeremiah 17, “I the LORD search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.”
Matthew 6, “But when thou doest alms, let not thy left hand know what thy right hand doeth: that thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly.”
John 2, “But Jesus did not commit himself unto them, because he knew all men, and needed not that any should testify of man: for he knew what was in man.”
John 16, “Now are we sure that thou knowest all things, and needest not that any man should ask thee: by this we believe that thou camest forth from God.”
John 21, “And he [Peter] said unto him [Jesus], Lord, thou knowest all things.”
1st Corinthians 2, “But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God. For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.”
1st John 3, “For if our heart condemn us, God is greater than our heart, and knoweth all things.”
For some relevant reading, see:
The following articles are based on the referenced Hitchensvs. McGrath debate:
Christopher Hitchens – On the Mutilation of Children’s Genitalia
Christopher Hitchens – Theological Fallacies and Miscomprehensions