So when someone comes to a Pastor or Priest requesting baptism, they’re supposed to “demand existential proof” first? Yeah, that will REALLY help spread the good news.
You have to know if your pastor/priest is a fake...or if he is real.
Any Pastor or Priest worth his salt is going at least interview a candidate for baptism first. If he claims to be a Pastor or Priest, he should also have the gift of the Holy Spirit to discern whether or not the candidate is sincere.