The Fed issues $1,000. They then rent those dollars to the bank. What does the bank do? The bank rents those dollars out to people so they can by a car, a home, whatever. They say: We'll rent this out to you and it'll be at five percent interest.
Now, what that means is they've taken a thousand – and if they have $1,000, the banks are allowed to loan out $17,000. So let's say you have ten percent interest on $17,000. Now that's $10,000 plus another $7,000.
Where does the $7,000 come from to pay it back? It wasn't ever issued. It didn't ever exist! How can they pay back more than there ever was? And people don't understand the concept of fiat money!