The difference is that God is an unfalsifiable claim.
The simulation argument is one that can be supported or argued against using evidence.
For example, if scientists find some new nature process that would be very difficult to simulate, (infinite speed of light is one such example) then that is strong evidence that we aren't in a simultion.
Of course, even if we keep observing things about the universe that would make it easier to simulate, that doesn't mean we actually are. It could just all be a coincidence. Or maybe it doesn't make any sense for a universe to be difficult to simulate.
The basic idea is to ask the question "Assume someone lives in a simulation. What would that person be likely/unlikely to observe?". and "Assume someone does NOT live in a simulation. What would they be likely/unlikely to observe?" And see how much this stuff matches up with reality.
The simulation argument is one that can be supported or argued against using evidence.
For example, if scientists find some new nature process that would be very difficult to simulate, (infinite speed of light is one such example) then that is strong evidence that we aren't in a simultion.
Of course, even if we keep observing things about the universe that would make it easier to simulate, that doesn't mean we actually are. It could just all be a coincidence. Or maybe it doesn't make any sense for a universe to be difficult to simulate.
The basic idea is to ask the question "Assume someone lives in a simulation. What would that person be likely/unlikely to observe?". and "Assume someone does NOT live in a simulation. What would they be likely/unlikely to observe?" And see how much this stuff matches up with reality.