Nancy Pelosi famously declared, "We must vote for (Obamacare) to find out what's in it."

With so many federal departments and agencies running off the rails from scandals and from utter arrogance by their public servants, and in view of our astoundingly large government debt, I propose the reverse of the Pelosi rule, as follows: 

"We have to eliminate agencies and departments to find out whether we need them."

If we are unsure whether a given agency or department is doing more harm than good, or if there is a question whether it is needed at all, then simply disband it, fire all of its employees, and then find out whether it is actually needed. 

Take note if and how much private citizens complain about the absence of government.   If necessary, then restart (with all new people) whatever small part of the department's functionality is necessary to address their specific concerns.   After a decent interval, whatever does not get restarted in this way automatically loses all of its enabling authority, and all of its past regulations become defunct.  

We will learn in this way that most of the federal government won't be missed.   More likely the prevailing attitude will be "good riddance."

This approach would emulate much of the positive creative destruction of free market capitalism, and it could rather quickly enable the federal budget to be balanced with minimal pain.  

Obvious first candidates for this approach are the departments of education and agriculture, the EPA, and most of commerce, interior and energy.