Yes overtime a misfire can ruin and damage an engine especially when the engine misfire gets worse.
If your engine is misfiring you should get it checked as soon as possible.
Possible causes of an engine misfire are, bad spark plugs, spark plug wires, ignition coil or ignition coils if your vehicle has more than one ignition coil.
Other causes of an engine misfire could be distributor or distributor cap, Distributor Rotor if your vehicle has one or your engines ignition timing has got out of correct settings.
When an engine is misfiring the fuel cannot be burnt properly and won't allow the engine to run properly.