The probability we are in a simulation depends on a bunch of assumptions. Assuming specifically we are asking about a "historical simulation", that the parent universe is identical to ours, we can change the question. Instead ask what is the probability we will someday create historical simulations of our past.
Technology certainly seems to advance over time, and the upper limits on computational power are extremely generous. So it's possible we could someday have the technology to do it. Assuming that, then it just depends on the probability you think we will want to make simulated beings. Something about that seems kind of sick and immoral, so I am skeptical of that assumption.
But if it is true, then the probability you are in a simulation is extremely high. Because the number of simulated beings could easily be orders of magnitude higher than the number of actual 2016 Earth inhabitants. Provided that many different simulations are run.
The quantum machanics behave disturbingly close to lazy evaluation - so this would not be surprising too.
Everyone of us is a god to a colony of ants.
Religions have a traceable history, which shows they were entirely man made. No need to prove or disprove that this or that person talked to "angels" since angels don't exist to begin with.Therefore there is no truthful prophet.