Riba

Allah has permitted trade and forbidden Riba.

Riba is Haram.

Paper money is Riba.

Use the Syariah currency.

Those who devour usury will not stand except as stand one whom the Evil one by his touch Hath driven to madness. That is because they say: "Trade is like usury," but Allah hath permitted trade and forbidden usury. Those who after receiving direction from their Lord, desist, shall be pardoned for the past; their case is for Allah (to judge); but those who repeat (The offence) are companions of the Fire: They will abide therein (for ever). ( Al-Baqarah 2:275 )