Certainty vs Freedom?

God does not "compel" acceptance of his authority, or we would not be free. Thus, the typical atheist who asks for miracles in order for God to "prove" his existence is really asking for God to remove his freedom. But that is something he will never do.
--Gagdad Bob

I've encountered Bob's argument above many times and in many places, but I've never understood it. What kind of "freedom" is Bob talking about? I take him to mean that if God doesn't prove himself to us, we have the freedom to either believe or not believe that He exists, whereas if God did prove himself to us, we would be compelled by that proof to know that He exists. There would be no freedom to disbelieve that He exists.

Yet, why is it better to believe in something that may or, for all we know, may not exist than to know that it exists? I've never understood why God would prefer the former to the latter. In fact, it seems to me that He would prefer the former. That is, He would want us to worship only a God whom we know to exist rather than to worship one who, for all we know, may be an illusory God or even a real devil.

Moreover, it seems to me that even if our freedom to disbelieve in God's existence is removed by compelling proof that He exists, we would still have the freedom to either "accept his authority"--i.e., obey His commands--or not accept it, just as a child who knows that his human father exists can choose to either accept or not accept his authority. Why would it be better for the child to only believe that his father exists and commands him to act in certain ways than it would be to know that he exists and that he issues those commands? Can't the child still choose to accept his father's authority and obey his commands or to not do so?

So, again, why is it better to merely believe that God exists than it is to know that He does? And, it if isn't, why doesn't God "prove his existence"?