I found this interesting quote from Henry Nelson Wieman, in a collection of essays in the second volume of the Library of Living Theologians.
It is claimed that God is free to make himself known to whom he will and in the way he chooses without regard to the limitations of the human mind in those who receive this gift of knowledge direct from God.
Theologians who understand God's freedom in this manner claim to have received knowledge of God in this way: namely, in a way beyond the power of the human mind to know. But notice what this means.
It means that people who claim to have this kind of knowledge of God are not so much claiming the freedom of God; they are claiming for themselves the freedom to know beyond the power of the human mind.
It is not God they are exalting so much as themselves. An individual or fellowship claiming to be the recipient of God's grace in such wise as to know what human methods of inquiry cannot know, is claiming to be as God.