In my answer to Can man judge whether God is fair?, I gave an example of the prophet Habakkuk questioning God in a judgmental way. God dealt with Habakkuk patiently, answering his questions.
On the other hand, as that question points out, there are people who judge God by deciding He is not fair that therefore should not be worshipped or trusted.
How do you draw the line between judging and questioning God? Is it ok to question God, but not to judge Him?