I think many people who are religious claim something like this, but very few of the actual teachings of religions claim this. They generally claim that God is unknowable (except for some Christians who claim a 'personal' relationship with God, and Mormons who claim God was once like us and we can be like him eventually). What they do claim is that God, in His eternal, omnipresent, and omnipotent wisdom has decided to give us some guidance for understanding the world around us and the spiritual realities of our existence. If we accept an eternal, omnipresent, and omnipotent God, there is no reason to assume he wouldn't try to give us guidance (or that he would). But claiming that he does, in and of itself, does not mean God is being put in a box. Now there are those who then take that to mean an exclusive knowledge of God, that's on them.