This is a big, big subject. Let me point out that most of the financial transactions we engage in are based on projections of future revenues -- the mortgage on your house, your investments in stocks, a company's investment in plant and equipment for anticipated market growth -- the whole world runs on it. If you try to run an entire economy on current revenues, you soon wind up with no revenues to run on.
The problem with government's handling of it is that it's often based on unrealistic projections. That's a big part of what happened here in NJ, for example. Politics get involved, and it's in the political interest of the officials in power to make rosy projections. They won't be around when the bills come due. As least, that's true most of the time. The net effect is that we tend to dig unmanageable holes -- at least, at the state level.
As for the accumulated national debt, that's another big, big issue. I'll make the point that you don't EVER, EVER want to pay off the national debt. Not if it's well-invested in things that lead to growth in our economy.
I'll drop one oversimplified example and then I'll go away. If the government borrows money and uses it to build infrastructure, or to run services that make money or prevent the loss of money (like the SEC), then the interest on US Treasury bonds are going to cost us a lot less than the revenue made with that investment -- or in the case of deficit spending during a recession, a lot less than the loss caused by a collapse in consumption.
From there, it gets very sticky. I'll just finish by saying that there is NO real, evidence-based or numbers-based economic thinking that says it's wise to reduce spending during a recession. None. A sovereign nation is not a household. If you apply the methods you use for managing your household income to a sovereign nation, that nation goes broke. At the national level, there is no place to invest money, except in your own economy. We can't buy Enron, or even Treasury bonds, because that's nothing but a circular money trail and a delusion. I don't want us to buy French Treasury bonds, either.
This stuff ain't easy. If anyone gives you an easy answer, back away carefully.