First, our living in a simulation means that we do not exist in the traditional sense. Living in a traditional sense implies you exist, everyone else exists, and the Universe exists as well. In example, if the Universe is a hologram then we would perceive ourselves to be living normally, while in fact the world is not what we perceive it to be. Many people may have existential crisis, since being told you are in a simulation can be quite a shock. However, the simulation world will still follow the rules of the Universe we. This means that the laws that govern our society are not changed. If we discover we are in a simulation, gravity will not cease to exist. Just because we found out we are in a simulation does not mean that the laws of nature have changed.
Possibly the largest implication would be the effect this knowledge would have on religion. Most religions are based around either a single god or a group of gods that created the world or have some on-going impact on our everyday lives. If we discover that the Universe was made by some higher-order beings than there are two ways the religious can respond: either they shift their identification of god to those that made the simulation or they can denounce their religion. There is a third option, ignorance, which some may choose but does not need explanation as to the change involved. There will always be people that will not believe the evidence brought forth if we are found to be part of a simulation.
If religions reimagine their god(s) to be the creator(s) of the simulation, they will have undeniable proof that god exists (assuming we have undeniable proof of being in a simulation, which I know to be difficult to explain). If every religion updates their definition of god then every religion will end up praying to the same creators. Perhaps one religion will emerge from the chaos that would ensue, a hybrid religion that combines what we currently believe with what we have learned from being in a simulation. However if religions cannot adapt their definitions of god then they will struggle while trying to maintain their previous assumptions. Finding proof that we live in a simulation will result in huge changes to society, for better or worse.
- Adin Adler