Here is a criticism about God’s omniscience and omnipotence
based upon a point made by John D. barrow in Impossibility, drawing on the work of cognitive scientists Donald
Mackay. To put it into simple terms, it might be easier to state it as follows:
It has long been understood that with God’s omniscience, he
cannot be contrary to his own predictions. For example, if you were claimed as
being omniscient and omnipotent and you predicted beforehand that you would
make yourself spaghetti bolognaise for supper on Friday, then when it came to
making Friday’s supper, you would have no choice but to make the spaghetti
bolognaise. This is because if you decided to be contrary to your own
prediction and cook, say, pizza, then your prediction would be incorrect. This
would render your omniscience faulty, and would leave you with the
characteristic of fallibility. God does not have omnipotence, because he cannot
do something that would invalidate his infallible predictions.
So, logically, God can never be contrary to his own
predictions. This constrains his free will quite significantly. However, it is
far more serious than this. If he is creating the universe and knowing every
particular outcome (even if one argues that he is somehow still allowing free
will), then he has made predictions about every event that will come to pass. His
foreknowledge is effectively one long prediction.
Thus, from the beginning of time onwards, everything must
come to pass exactly as God has predicted at the actualisation of the cosmos. This
has far-reaching consequences: God does not have free will, intercessory prayer
is pointless, God cannot change his mind, and the passage in the bible where God
changed his mind over the fate of Nineveh
is patently false.
When God saw their deeds, that they turned from their wicked
way, then God relented concerning the calamity which He had declared He would bring
upon them. And He did not do it.