You cannot say what god is but you can say what he is not. God is good = God is not evil, because we cannot really know what we mean by "god is good". God is not a human being because God is transcendent.
God is totally beyond human comprehension.God is ineffable.We could say that God is good or all-knowing, but our knowledge of goodness is that of a human being.This means that saying these things tells us nothing about God.We can debate what it means for God to be all-knowing but we cannot ultimately know what it is to be all-knowing.
BUT it is useful when talking about an ineffable religious experience.
CriticismHow long would we need to go on before we reach a conclusion of what god is? If it cannot be clearly stated what is being talked about, how can we be sure there is anything at all?Pseudo-DyonisisGod is beyond assertion and beyond denial. Whatever you say about God tells us nothing about him, whether you say what he is or what he is not.
The Via Negativa