I recently heard atheist Dan Barker say God cannot be both all-powerful and all-knowing. The general idea appears to be that if God is all-powerful, He would have the ability to change His mind, but if He could change His mind at some point in the future, He would not know everything. Barker says “These are not just contradictions. These show He cannot exist.” I have heard this before in statements floating around atheist circles.
However, this argument is a false dilemma, born out of a misunderstanding of theology and an apparent zeal for finding reasons for not trusting God. The following is Greg Koukl’s explanation of Richard Dawkin’s similar mistake:
Part of the reason that atheists miss this point so broadly is due to Christians, who with a general lack of theological instruction, throw around terms without understanding what is behind them. Such statements spill over into misunderstandings in non-Christians. But those who go in public and try to make statements about it should think through their positions before making the errors of Dawkins and Barker and their disciples.
Despite Christians’ lack of ability to explain their own doctrines, such false dilemmas of pop atheists should be disregarded. Most of these ‘gotcha’ type arguments about God come from either logical false dilemmas, such as God making rocks so heavy He cannot lift, or a false view of theology. A good study in systematic theology would do all people some good.