Most reasonable people have decided that everyone gets to have an unsubstantiated belief system that goes into the “Religion” slot and it’s not a big deal as long as no one makes it a Big Deal. Reasonable people have decided this because trying to proactively eliminate it is way harder and god-awful than just letting it ride (once again, as long as no one makes it a Big Deal).
USD Inflation is ~3% per year currently, which is easy to beat with a high yield savings account. Anything more than 6 months should definitely go into an index fund though.