Taxes do not and cannot fund anything. Taxes actually destroy money same as if you chucked it all on a big bonfire. To us, every $ is credit. But to the govt (the currency issuer) all money is debt. So many IOUs. What happens when an IOU is returned to you? The debt simply ceases to exist.
What the "debt" actually represents is so many deposits at the national bank - the treasuries/gilts. If a bank has lots of customers, is that really a problem..?
I understand that this debt is what we call a "public deficit" in Europe. Obviously, this is a complex issue, and it's difficult to discuss it in just a few words.