ALL cash is credit. Any money you have in your bank account exists because of either an existing private sector loan or a government liability. So if your economy depends on money (and it does), then it also depends on debt.
1. Can you demonstrate that the debt is even harmful to the economy?
2. GDP = C + G + I + (X - M). Since the government (when not in surplus) spends every cent that it takes in, but consumers don't spend every cent that they earn (and wouldn't spend 100% of their tax savings, either), the only logical conclusion that one can come to regarding taxes and the GDP equation is that lowering or eliminating G would, all else being equal, lower GDP itself. How does that make the economy stronger?
3. The debt is in the hands of banks, China, pension funds, various rich guys, etc., while taxation would come primarily from income taxes - money coming out of the active economy. How do you plan on eliminating the debt when you can't reach these bondholders through taxation?